.course-shell {
  padding-top: 12px;
}

/* Course calm24: common-mistake band must show full diagnostic text. */
@media (min-width: 1181px) {
  body .lesson-mistake-panel,
  body .lesson-studio .lesson-mistake-panel,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel {
    grid-template-rows: minmax(118px, auto) !important;
    min-height: 118px !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-mistake-panel .mistake-card,
  body .lesson-mistake-panel .completion-evidence,
  body .lesson-mistake-panel .complete-button,
  body .lesson-studio .lesson-mistake-panel .mistake-card,
  body .lesson-studio .lesson-mistake-panel .completion-evidence,
  body .lesson-studio .lesson-mistake-panel .complete-button {
    min-height: 118px !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-mistake-panel .mistake-card p:last-child,
  body .lesson-studio .lesson-mistake-panel .mistake-card p:last-child {
    display: block !important;
    -webkit-line-clamp: unset !important;
    -webkit-box-orient: initial !important;
    overflow: visible !important;
  }

  body .lesson-mistake-panel .completion-evidence span,
  body .lesson-studio .lesson-mistake-panel .completion-evidence span {
    display: block !important;
    overflow: visible !important;
  }
}

/* Course calm22: add the reference-like bottom visual model engine rail. */
@media (min-width: 1181px) {
  body .lesson-studio-shell {
    grid-template-rows: 68px minmax(0, 1fr) !important;
  }

  body .learning-flow.course-flow.lesson-studio {
    grid-template-rows: 514px 126px 72px !important;
  }

  body .lesson-studio .model-card {
    grid-template-rows: 54px 32px 0 minmax(0, 306px) 0 !important;
    min-height: 420px !important;
    max-height: 420px !important;
  }

  body .lesson-studio .visual-stage {
    min-height: 306px !important;
    height: 306px !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: minmax(0, 252px) 36px !important;
    max-height: 286px !important;
  }

  body .lesson-studio .visual-stage .desktop-equation-balance {
    height: 252px !important;
    max-height: 252px !important;
  }

  body .lesson-inspector {
    grid-template-rows: 78px minmax(0, 170px) 70px 94px !important;
  }

  body .lesson-practice {
    min-height: 126px !important;
    max-height: 126px !important;
    padding: 12px !important;
  }

  body .lesson-practice h2 {
    font-size: 17px !important;
  }

  body .lesson-practice .practice-card {
    padding: 9px !important;
  }

  body .lesson-mistake-panel {
    min-height: 72px !important;
    max-height: 72px !important;
  }

  body .lesson-mistake-panel .complete-button {
    min-height: 72px !important;
  }

  body .course-model-rail {
    display: grid !important;
    grid-template-columns: 150px minmax(0, 1fr) !important;
    gap: 10px !important;
    align-items: stretch !important;
    min-height: 74px !important;
    height: 74px !important;
    max-height: 74px !important;
    margin-top: 10px !important;
    padding: 9px 12px !important;
    border-radius: 22px !important;
    background: rgba(255, 255, 255, .78) !important;
    border: 1px solid rgba(114, 145, 155, .15) !important;
    box-shadow: 0 18px 46px rgba(43, 77, 105, .06) !important;
    overflow: hidden !important;
  }

  body .course-model-head {
    display: grid !important;
    align-content: center !important;
    gap: 2px !important;
    min-width: 0 !important;
  }

  body .course-model-head span {
    color: #1f6fdf !important;
    font-size: 12px !important;
    font-weight: 900 !important;
  }

  body .course-model-head strong {
    color: #173047 !important;
    font-size: 18px !important;
    line-height: 1 !important;
  }

  body .course-model-strip {
    display: grid !important;
    grid-template-columns: 190px repeat(11, minmax(70px, 1fr)) 92px !important;
    gap: 8px !important;
    min-width: 0 !important;
    overflow: hidden !important;
  }

  body .course-model-summary,
  body .course-model-chip,
  body .course-model-more {
    min-width: 0 !important;
    height: 54px !important;
    display: grid !important;
    align-content: center !important;
    text-decoration: none !important;
    border-radius: 16px !important;
    background: linear-gradient(180deg, rgba(255,255,255,.82), rgba(241,248,255,.72)) !important;
    border: 1px solid rgba(117, 150, 164, .16) !important;
    overflow: hidden !important;
  }

  body .course-model-summary {
    padding: 8px 10px !important;
    background: linear-gradient(135deg, rgba(232, 248, 244, .96), rgba(237, 246, 255, .92)) !important;
    border-color: rgba(47, 123, 112, .16) !important;
  }

  body .course-model-summary span,
  body .course-model-summary small,
  body .course-model-chip small,
  body .course-model-more small {
    color: #66818d !important;
    font-size: 10px !important;
    font-weight: 800 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .course-model-summary strong {
    color: #173047 !important;
    font-size: 18px !important;
    line-height: 1.08 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .course-model-chip {
    grid-template-columns: 18px minmax(0, 1fr) !important;
    grid-template-rows: 18px 18px !important;
    gap: 1px 6px !important;
    padding: 8px !important;
  }

  body .course-model-chip i {
    grid-row: 1 / 3 !important;
    align-self: center !important;
    width: 18px !important;
    height: 18px !important;
    display: grid !important;
    place-items: center !important;
    border-radius: 999px !important;
    background: rgba(47, 114, 214, .1) !important;
    color: #1f6fdf !important;
    font-size: 10px !important;
    font-style: normal !important;
    font-weight: 900 !important;
  }

  body .course-model-icon {
    display: none !important;
  }

  body .course-model-chip strong,
  body .course-model-more strong {
    color: #173047 !important;
    font-size: 12px !important;
    font-weight: 900 !important;
    line-height: 1.1 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .course-model-chip.is-active {
    background: linear-gradient(145deg, #2f72d6, #2f9a8a) !important;
    border-color: rgba(47, 114, 214, .22) !important;
    box-shadow: 0 12px 24px rgba(47, 114, 214, .16) !important;
  }

  body .course-model-chip.is-active i {
    background: rgba(255,255,255,.2) !important;
    color: #fff !important;
  }

  body .course-model-chip.is-active strong,
  body .course-model-chip.is-active small {
    color: #fff !important;
  }

  body .course-model-more {
    padding: 8px 10px !important;
    justify-items: center !important;
    text-align: center !important;
  }
}

@media (max-width: 1180px) {
  body .course-model-rail {
    display: none !important;
  }
}

/* Course calm23: final desktop safety overrides after legacy fixed-height passes. */
@media (min-width: 1181px) {
  html,
  body {
    min-height: 100% !important;
    overflow-x: hidden !important;
    overflow-y: auto !important;
  }

  body .course-system-shell {
    min-height: 100vh !important;
    height: auto !important;
    overflow: visible !important;
    align-items: start !important;
  }

  body .lesson-studio-shell {
    gap: 8px !important;
    min-height: 0 !important;
    height: auto !important;
    overflow: visible !important;
  }

  body .lesson-studio-shell .course-hero {
    grid-template-columns: minmax(0, 1fr) auto minmax(260px, 326px) !important;
    column-gap: 12px !important;
    overflow: visible !important;
  }

  body .lesson-studio-shell .course-nav {
    justify-self: end !important;
    width: min(326px, 100%) !important;
    min-width: 0 !important;
    max-width: 326px !important;
    margin-right: 4px !important;
  }

  body .lesson-studio-shell .course-nav .catalog-button {
    min-width: 0 !important;
  }

  body .learning-flow.course-flow.lesson-studio,
  body .lesson-studio {
    grid-template-columns: 138px minmax(0, 1fr) 302px !important;
    grid-template-rows: 500px 132px 82px !important;
    height: auto !important;
    min-height: 724px !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main {
    grid-template-rows: 68px 422px !important;
    height: 500px !important;
    min-height: 500px !important;
    max-height: 500px !important;
  }

  body .lesson-studio .course-prompt {
    min-height: 68px !important;
    height: 68px !important;
    max-height: 68px !important;
  }

  body .lesson-studio .course-prompt .choice-row button {
    min-height: 36px !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    min-height: 422px !important;
    height: 422px !important;
    max-height: 422px !important;
    grid-template-rows: 42px 26px 20px minmax(0, 314px) 0 !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    min-height: 314px !important;
    height: 314px !important;
    max-height: 314px !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board,
  body .learning-flow.course-flow.lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: minmax(0, 262px) 40px !important;
    max-height: 302px !important;
  }

  body .lesson-studio .visual-stage .desktop-equation-balance,
  body .learning-flow.course-flow.lesson-studio .visual-stage .desktop-equation-balance {
    height: 262px !important;
    max-height: 262px !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel button {
    min-height: 38px !important;
  }

  body .lesson-inspector {
    height: 500px !important;
    min-height: 500px !important;
    max-height: 500px !important;
    grid-template-rows: 86px 100px minmax(0, 158px) 64px 52px !important;
  }

  body .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    height: 132px !important;
    min-height: 132px !important;
    max-height: 132px !important;
    overflow: hidden !important;
  }

  body .lesson-practice .practice-list {
    grid-template-rows: 104px !important;
  }

  body .lesson-practice .practice-card {
    min-height: 104px !important;
    height: 104px !important;
    max-height: 104px !important;
    grid-template-rows: minmax(0, 44px) 38px !important;
  }

  body .lesson-practice .answer-options button,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options button {
    min-height: 36px !important;
  }

  body .lesson-mistake-panel,
  body .lesson-studio .lesson-mistake-panel {
    height: 82px !important;
    min-height: 82px !important;
    max-height: 82px !important;
  }

  body .lesson-mistake-panel .mistake-card,
  body .lesson-mistake-panel .completion-evidence,
  body .lesson-mistake-panel .complete-button {
    height: 82px !important;
    min-height: 82px !important;
    max-height: 82px !important;
  }

  body .course-model-rail {
    display: grid !important;
    min-height: 74px !important;
    height: 74px !important;
    max-height: 74px !important;
    margin-top: 8px !important;
  }

  html body .lesson-studio .lesson-practice .answer-options button,
  html body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options button,
  html body .lesson-studio .lesson-practice .practice-card:first-child .answer-options button,
  html body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .answer-options button,
  html body .lesson-studio .visual-stage .balance-step-panel button,
  html body .learning-flow.course-flow.lesson-studio .visual-stage .balance-step-panel button {
    min-height: 36px !important;
    height: 36px !important;
    max-height: none !important;
    line-height: 1.15 !important;
    padding-top: 7px !important;
    padding-bottom: 7px !important;
  }
}

/* Course calm3: focused lesson cockpit, PM/teaching/QA pass 2026-07-20. */
@media (min-width: 1181px) {
  body .course-system-shell {
    width: min(1500px, calc(100% - 18px)) !important;
    grid-template-columns: 150px minmax(0, 1fr) !important;
    gap: 10px !important;
    padding: 8px !important;
    background:
      radial-gradient(circle at 72% 5%, rgba(132, 194, 227, 0.18), transparent 27%),
      linear-gradient(180deg, #edf7ff 0%, #f8fcfb 56%, #faf6ef 100%) !important;
  }

  body .lesson-studio-shell {
    gap: 10px !important;
    overflow: hidden !important;
  }

  body .lesson-studio-shell .course-hero {
    min-height: 68px !important;
    padding: 11px 18px !important;
    border-radius: 20px !important;
  }

  body .lesson-studio-shell .course-hero h1 {
    font-size: 30px !important;
    line-height: 1.05 !important;
  }

  body .lesson-studio-shell .course-nav {
    min-width: 360px !important;
    max-width: 360px !important;
  }

  body .learning-flow.course-flow.lesson-studio {
    grid-template-columns: 126px minmax(0, 1fr) 260px !important;
    grid-template-rows: 562px 145px 87px !important;
    grid-template-areas:
      "steps main panel"
      "steps practice practice"
      "steps mistake mistake" !important;
    gap: 10px !important;
    align-items: stretch !important;
    min-height: 0 !important;
  }

  body .lesson-stepper {
    top: 82px !important;
    align-self: stretch !important;
    gap: 8px !important;
    padding: 8px !important;
    border-radius: 18px !important;
  }

  body .lesson-stepper a {
    grid-template-columns: 28px minmax(0, 1fr) !important;
    min-height: 62px !important;
    padding: 7px 8px !important;
    border-radius: 16px !important;
  }

  body .lesson-stepper b {
    width: 28px !important;
    height: 28px !important;
  }

  body .lesson-stepper small,
  body .lesson-stepper em {
    display: none !important;
  }

  body .lesson-stepper span {
    font-size: 12px !important;
    white-space: nowrap !important;
  }

  body .lesson-main {
    gap: 10px !important;
    min-height: 0 !important;
  }

  body .lesson-main .course-prompt {
    min-height: 92px !important;
    grid-template-columns: minmax(0, 1fr) 350px !important;
    padding: 14px 16px !important;
    border-radius: 22px !important;
    box-shadow: 0 18px 50px rgba(43, 77, 105, 0.08) !important;
  }

  body .lesson-main .course-prompt h2 {
    margin-top: 4px !important;
    font-size: 19px !important;
    line-height: 1.25 !important;
  }

  body .lesson-main .course-prompt .feedback {
    display: none !important;
  }

  body .lesson-main .choice-row {
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 8px !important;
  }

  body .lesson-main .choice-row button {
    min-height: 42px !important;
    border-radius: 14px !important;
    font-size: 12px !important;
  }

  body .lesson-studio .model-card {
    grid-template-rows: 58px 36px 0 minmax(0, 348px) 0 !important;
    min-height: 460px !important;
    max-height: 460px !important;
    border-radius: 24px !important;
  }

  body .lesson-studio .model-head {
    min-height: 48px !important;
    margin: 10px 10px 0 !important;
    padding: 8px 12px !important;
    border-radius: 16px !important;
  }

  body .lesson-studio .model-head .eyebrow {
    display: none !important;
  }

  body .lesson-studio .model-head h2 {
    font-size: 18px !important;
    line-height: 1.18 !important;
  }

  body .lesson-studio .formula-strip {
    min-height: 36px !important;
    max-height: 36px !important;
    margin: 0 10px !important;
    overflow: hidden !important;
  }

  body .lesson-studio .formula-pill {
    min-height: 28px !important;
    max-width: 34% !important;
    padding: 5px 10px !important;
    font-size: 11px !important;
  }

  body .lesson-studio .model-feedback,
  body .lesson-studio .course-controls {
    display: none !important;
  }

  body .lesson-studio .visual-stage {
    min-height: 348px !important;
    height: 348px !important;
    margin: 0 10px 10px !important;
    padding: 10px !important;
    border-radius: 18px !important;
    overflow: hidden !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board {
    width: min(100%, 760px) !important;
    grid-template-rows: minmax(0, 290px) 38px !important;
    gap: 8px !important;
    height: 100% !important;
    max-height: 328px !important;
    overflow: hidden !important;
    padding: 0 !important;
    border: 0 !important;
    background: transparent !important;
  }

  body .lesson-studio .visual-stage .desktop-equation-balance {
    display: block !important;
    grid-row: 1 !important;
    width: auto !important;
    max-width: 100% !important;
    height: 290px !important;
    max-height: 290px !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel {
    grid-row: 2 !important;
    min-height: 38px !important;
    padding: 0 !important;
    border: 0 !important;
    background: transparent !important;
    box-shadow: none !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel button {
    min-height: 36px !important;
    border-radius: 999px !important;
    font-size: 13px !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel span {
    display: none !important;
  }

  body .mobile-equation-balance {
    display: none !important;
  }

  body .mobile-equation-title {
    font-size: 24px !important;
    line-height: 1 !important;
  }

  body .mobile-pan {
    min-height: 148px !important;
    border-radius: 14px !important;
  }

  body .mobile-drag-zone {
    min-height: 58px !important;
  }

  body .result-zone {
    min-height: 78px !important;
    font-size: 28px !important;
  }

  body .lesson-inspector {
    align-self: stretch !important;
    grid-template-rows: 86px minmax(0, 183px) 75px 104px !important;
    gap: 10px !important;
    overflow: hidden !important;
  }

  body .lesson-inspector .mini-card {
    min-height: 0 !important;
    max-height: none !important;
    padding: 12px !important;
    border-radius: 18px !important;
    overflow: hidden !important;
  }

  body .lesson-inspector .problem-card h3 {
    font-size: 16px !important;
    line-height: 1.26 !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
  }

  body .lesson-inspector .mini-card p,
  body .lesson-inspector .mini-card li {
    font-size: 11.5px !important;
    line-height: 1.3 !important;
  }

  body .lesson-inspector .mini-card ol {
    gap: 6px !important;
    padding-right: 2px !important;
    overflow: auto !important;
  }

  body .lesson-neighbors .neighbor-list {
    gap: 0 !important;
  }

  body .lesson-neighbors .neighbor-link {
    min-height: 42px !important;
    padding: 8px 10px !important;
  }

  body .lesson-neighbors .neighbor-link:not(:first-child),
  body .lesson-neighbors .neighbor-link small,
  body .lesson-neighbors .neighbor-link b {
    display: none !important;
  }

  body .lesson-practice {
    display: grid !important;
    grid-template-columns: 168px minmax(0, 1fr) !important;
    gap: 12px !important;
    align-items: stretch !important;
    min-height: 145px !important;
    max-height: 145px !important;
    padding: 14px !important;
    border-radius: 22px !important;
    overflow: hidden !important;
  }

  body .lesson-practice h2 {
    margin: 4px 0 0 !important;
    font-size: 18px !important;
    line-height: 1.18 !important;
  }

  body .lesson-practice .practice-list {
    display: grid !important;
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 10px !important;
    min-height: 0 !important;
  }

  body .lesson-practice .practice-card {
    display: grid !important;
    grid-template-rows: minmax(0, 1fr) auto !important;
    gap: 8px !important;
    min-height: 0 !important;
    padding: 10px !important;
    border-radius: 18px !important;
    overflow: hidden !important;
  }

  body .lesson-practice .practice-card-head,
  body .lesson-practice .practice-question span,
  body .lesson-practice .practice-question small,
  body .lesson-practice .practice-diagnosis {
    display: none !important;
  }

  body .lesson-practice .practice-question {
    min-height: 0 !important;
  }

  body .lesson-practice .practice-question strong {
    font-size: 14px !important;
    line-height: 1.25 !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
  }

  body .lesson-practice .answer-options {
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 7px !important;
  }

  body .lesson-practice .answer-options button {
    min-height: 36px !important;
    border-radius: 12px !important;
    font-size: 12px !important;
  }

  body .lesson-mistake-panel {
    grid-template-columns: minmax(0, 1fr) 220px !important;
    align-items: stretch !important;
    gap: 12px !important;
    min-height: 87px !important;
    max-height: 87px !important;
  }

  body .lesson-mistake-panel .mini-card {
    min-height: 0 !important;
    padding: 12px 14px !important;
    border-radius: 20px !important;
    overflow: hidden !important;
  }

  body .lesson-mistake-panel .mini-card p:last-child {
    margin: 5px 0 0 !important;
    font-size: 12px !important;
    line-height: 1.35 !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
  }

  body .lesson-mistake-panel .complete-button {
    min-height: 87px !important;
    border-radius: 20px !important;
  }
}

@media (max-width: 760px) {
  body .lesson-studio-shell .course-hero {
    padding: 12px 14px !important;
    border-radius: 22px !important;
  }

  body .lesson-main .course-prompt {
    margin-top: 2px !important;
    box-shadow: 0 12px 28px rgba(43, 77, 105, 0.08) !important;
  }

  body .lesson-studio .model-card {
    box-shadow: 0 16px 36px rgba(43, 77, 105, 0.11) !important;
  }

  body .lesson-practice {
    border-radius: 20px !important;
    background: rgba(255, 255, 255, 0.82) !important;
  }
}

/* Course mobile focus2 2026-07-20: one action, one model, visible feedback. */
@media (max-width: 760px) {
  .lesson-studio-shell {
    --mobile-gutter: clamp(10px, 3vw, 14px);
  }

  .lesson-dashboard-strip,
  .lesson-journey,
  .lesson-proofbar,
  .lesson-action-board {
    display: none !important;
  }

  .lesson-stepper {
    display: flex !important;
    align-items: center !important;
    min-height: 38px !important;
    margin: 0 0 8px !important;
    padding: 5px !important;
    border-radius: 999px !important;
    overflow: hidden !important;
    background: rgba(255, 255, 255, .66) !important;
    border-color: rgba(120, 148, 156, .16) !important;
  }

  .lesson-stepper a {
    display: none !important;
  }

  .lesson-stepper a.is-active,
  .lesson-stepper a[aria-current="step"] {
    display: grid !important;
    grid-template-columns: 28px minmax(0, 1fr) !important;
    width: 100% !important;
    min-height: 28px !important;
    padding: 3px 12px 3px 4px !important;
    border-radius: 999px !important;
    background: #ffffff !important;
  }

  .lesson-stepper a.is-active::after,
  .lesson-stepper a[aria-current="step"]::after {
    content: "第 2 / 6 步";
    justify-self: end;
    align-self: center;
    color: rgba(37, 62, 70, .58);
    font-size: 11px;
    font-weight: 800;
  }

  .lesson-main {
    gap: 8px !important;
  }

  .lesson-main .course-prompt {
    min-height: 78px !important;
    padding: 10px 12px !important;
    border-radius: 18px !important;
    background: rgba(255, 255, 255, .78) !important;
  }

  .lesson-main .course-prompt .eyebrow,
  .lesson-main .course-prompt .choice-row,
  .lesson-main .course-prompt .feedback {
    display: none !important;
  }

  .lesson-main .course-prompt h2 {
    font-size: 18px !important;
    line-height: 1.2 !important;
    letter-spacing: 0 !important;
    display: block !important;
    -webkit-line-clamp: unset !important;
    overflow: visible !important;
  }

  .lesson-studio .model-card {
    grid-template-rows: 56px 42px 42px minmax(0, 322px) 0 !important;
    min-height: 486px !important;
    max-height: 486px !important;
    border-radius: 20px !important;
  }

  .lesson-studio .model-head {
    grid-template-columns: minmax(0, 1fr) auto !important;
    min-height: 46px !important;
    margin: 8px 8px 0 !important;
    padding: 7px 9px !important;
    border-radius: 14px !important;
  }

  .lesson-studio .model-head .eyebrow {
    display: none !important;
  }

  .lesson-studio .model-head h2 {
    font-size: 15px !important;
    line-height: 1.16 !important;
    -webkit-line-clamp: 2 !important;
  }

  .lesson-studio .model-head .ghost-button {
    min-width: 46px !important;
    min-height: 32px !important;
    padding: 0 9px !important;
    font-size: 11px !important;
    opacity: .78 !important;
  }

  .lesson-studio .formula-strip {
    min-height: 42px !important;
    max-height: 42px !important;
    margin: 0 8px !important;
  }

  .lesson-studio .formula-pill {
    min-height: 26px !important;
    padding: 4px 8px !important;
    font-size: 10px !important;
  }

  .lesson-studio .model-feedback {
    display: block !important;
    min-height: 38px !important;
    max-height: 38px !important;
    margin: 0 8px !important;
    padding: 6px 10px !important;
    border-radius: 14px !important;
    font-size: 12px !important;
    line-height: 1.2 !important;
    overflow: hidden !important;
    color: #17463f !important;
    background: rgba(229, 247, 239, .92) !important;
    border: 1px solid rgba(74, 154, 130, .26) !important;
  }

  .lesson-studio .visual-stage {
    min-height: 322px !important;
    height: 322px !important;
    margin: 0 8px !important;
    padding: 7px !important;
    border-radius: 16px !important;
  }

  .lesson-studio .course-controls {
    min-height: 0 !important;
    max-height: 0 !important;
    margin: 0 !important;
    padding: 0 !important;
    overflow: hidden !important;
  }

  .lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: 40px minmax(0, 268px) !important;
    gap: 7px !important;
    max-height: 308px !important;
  }

  .lesson-studio .visual-stage .balance-step-panel {
    min-height: 40px !important;
  }

  .lesson-studio .visual-stage .balance-step-panel button {
    width: 100% !important;
    min-height: 40px !important;
    border-radius: 999px !important;
    font-size: 14px !important;
    box-shadow: 0 10px 22px rgba(30, 115, 92, .16) !important;
  }

  .lesson-studio .visual-stage .balance-step-panel span {
    display: none !important;
  }

  .mobile-equation-balance {
    height: 268px !important;
    grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
    gap: 7px !important;
    overflow: hidden !important;
  }

  .mobile-equation-title {
    grid-column: 1 / -1 !important;
    font-size: 21px !important;
  }

  .mobile-balance-beam {
    grid-column: 1 / -1 !important;
    height: 7px !important;
  }

  .mobile-pan {
    min-height: 124px !important;
    padding: 7px !important;
    gap: 5px !important;
  }

  .mobile-drag-zone {
    min-height: 44px !important;
    gap: 4px !important;
  }

  .result-zone {
    min-height: 64px !important;
    font-size: 25px !important;
  }

  .mini-x,
  .mini-one,
  .mini-neg,
  .mini-zero {
    min-width: 27px !important;
    min-height: 25px !important;
    font-size: 13px !important;
  }

  .mobile-equation-balance p {
    grid-column: 1 / -1 !important;
    min-height: 31px !important;
    margin: 0 !important;
    padding: 4px 8px !important;
    border-radius: 12px !important;
    background: rgba(255, 255, 255, .7) !important;
    font-size: 12px !important;
    line-height: 1.18 !important;
    white-space: normal !important;
    overflow: hidden !important;
    text-overflow: clip !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
  }

  .lesson-main .course-prompt {
    order: 1 !important;
    grid-row: 1 !important;
  }

  .lesson-studio .model-card {
    order: 2 !important;
    grid-row: 2 !important;
  }

  .lesson-studio .model-head {
    grid-row: 1 !important;
  }

  .lesson-studio .formula-strip {
    grid-row: 2 !important;
  }

  .lesson-studio .model-feedback {
    grid-row: 3 !important;
  }

  .lesson-studio .visual-stage {
    grid-row: 4 !important;
  }

  .lesson-studio .course-controls {
    grid-row: 5 !important;
  }
}

.course-system-shell {
  display: block;
}

.course-sidebar {
  display: none;
}

.course-brand,
.course-side-nav a,
.course-side-cta {
  color: inherit;
  text-decoration: none;
}

.course-brand {
  display: flex;
  align-items: center;
  gap: 9px;
}

.course-brand span {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 10px;
  background: linear-gradient(145deg, #2f87ff, #155bc5);
  color: #ffffff;
  font-size: 13px;
  font-weight: 900;
  box-shadow: 0 10px 22px rgba(31, 111, 229, 0.24);
}

.course-brand strong {
  color: #123466;
  font-size: 18px;
  line-height: 1;
}

.course-side-nav {
  display: grid;
  gap: 5px;
}

.course-side-nav a {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  align-items: center;
  gap: 8px;
  min-height: 36px;
  border-radius: 8px;
  padding: 0 8px;
  color: #4c5e77;
  font-size: 12px;
  font-weight: 780;
}

.course-side-nav i {
  display: grid;
  width: 24px;
  height: 24px;
  place-items: center;
  border: 1px solid rgba(31, 111, 229, 0.1);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  color: #55708c;
  font-size: 11px;
  font-style: normal;
  font-weight: 900;
}

.course-side-nav span {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-side-nav a:hover,
.course-side-nav a.is-active {
  background: #eaf3ff;
  color: #155bc5;
}

.course-side-nav a:hover i,
.course-side-nav a.is-active i {
  border-color: rgba(31, 111, 229, 0.18);
  background: #1f6fe5;
  color: #ffffff;
  box-shadow: 0 8px 18px rgba(31, 111, 229, 0.2);
}

.course-side-card {
  display: grid;
  gap: 6px;
  margin-top: auto;
  border: 1px solid rgba(42, 166, 120, 0.16);
  border-radius: 8px;
  background: linear-gradient(180deg, #fbfffd, #edf9f3);
  padding: 12px;
}

.course-side-card span,
.course-side-card small {
  color: #607080;
  font-size: 11px;
  font-weight: 760;
}

.course-side-card strong {
  color: #17384a;
  font-size: 14px;
  line-height: 1.22;
  overflow-wrap: anywhere;
}

.course-side-card small {
  color: #287b73;
}

.course-side-cta {
  display: grid;
  min-height: 34px;
  place-items: center;
  border-radius: 8px;
  background: linear-gradient(135deg, #287b73, #2aa678);
  color: #ffffff;
  font-size: 12px;
  font-weight: 850;
  box-shadow: 0 12px 24px rgba(40, 123, 115, 0.16);
}

body {
  background:
    linear-gradient(115deg, rgba(31, 111, 229, 0.055) 0 18%, transparent 18% 100%),
    radial-gradient(circle at 14% -12%, rgba(53, 125, 222, 0.14), transparent 34%),
    radial-gradient(circle at 88% 0%, rgba(131, 180, 234, 0.12), transparent 28%),
    linear-gradient(180deg, #f8fbff 0%, #eff6ff 48%, #fbfdff 100%);
}

.lesson-studio-shell {
  color: #10233f;
}

.course-nav {
  position: sticky;
  top: 8px;
  z-index: 20;
  display: grid;
  grid-template-columns: 44px minmax(0, 220px) 44px;
  justify-content: center;
  gap: 8px;
  margin: 0 auto 10px;
}

.nav-button,
.catalog-button,
.complete-button {
  border: 1px solid rgba(64, 111, 178, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.86);
  color: #17384a;
  box-shadow: 0 12px 34px rgba(38, 77, 130, 0.07);
  backdrop-filter: blur(22px) saturate(145%);
  cursor: pointer;
}

.nav-button {
  width: 44px;
  min-height: 44px;
  font-size: 22px;
}

.catalog-button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 14px;
}

.catalog-button span {
  color: #55706f;
  font-size: 12px;
}

.catalog-button strong {
  font-size: 14px;
}

.course-hero {
  position: relative;
  top: auto;
}

.course-hero h1 {
  font-size: 44px;
}

.course-flow {
  align-items: start;
}

.course-prompt {
  top: 68px;
}

.course-controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 10px;
  margin: 14px 18px 0;
}

.course-controls:empty {
  display: none;
}

.direct-manipulation-cue {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border: 1px solid rgba(38, 112, 109, 0.22);
  border-radius: 8px;
  background:
    radial-gradient(circle at 18% 20%, rgba(255, 255, 255, 0.95), transparent 32%),
    linear-gradient(135deg, rgba(247, 253, 251, 0.96), rgba(237, 246, 255, 0.9));
  padding: 13px 14px 13px 48px;
  color: #17384a;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.88), 0 14px 28px rgba(37, 55, 78, 0.08);
}

.direct-manipulation-cue::before {
  content: "";
  position: absolute;
  left: 14px;
  width: 22px;
  height: 22px;
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.88), rgba(204, 234, 228, 0.96));
  box-shadow: 0 8px 18px rgba(40, 123, 115, 0.16), inset 0 1px 0 rgba(255, 255, 255, 0.9);
  transform: rotate(-8deg);
}

.direct-manipulation-cue strong {
  flex: 0 0 auto;
  color: #287b73;
  font-size: 13px;
  font-weight: 900;
}

.direct-manipulation-cue span {
  min-width: 0;
  color: #3c5b67;
  font-size: 13px;
  font-weight: 720;
  line-height: 1.45;
}

.direct-manipulation-cue em {
  flex: 0 0 auto;
  border-radius: 999px;
  background: rgba(40, 123, 115, 0.12);
  padding: 5px 9px;
  color: #287b73;
  font-size: 11px;
  font-style: normal;
  font-weight: 900;
}

.model-feedback {
  margin: 10px 18px 0;
  border: 1px solid rgba(38, 112, 109, 0.16);
  border-radius: 8px;
  background: rgba(247, 253, 251, 0.78);
  padding: 10px 12px;
  color: #3c5b67;
  font-size: 13px;
  font-weight: 720;
}

.model-feedback.is-active {
  border-color: rgba(45, 115, 214, 0.24);
  background: #edf6ff;
  color: #17384a;
}

.course-control {
  display: grid;
  gap: 8px;
  border: 1px solid rgba(35, 103, 137, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  padding: 12px;
}

.course-control span {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: #27405b;
  font-size: 13px;
  font-weight: 700;
}

.course-control input {
  width: 100%;
  accent-color: #287b73;
}

.course-stage {
  display: grid;
  place-items: center;
  min-height: 430px;
  height: auto !important;
  padding: 26px;
}

.course-stage.is-direct-stage {
  min-height: 500px;
  background:
    radial-gradient(circle at 22% 18%, rgba(255, 245, 210, 0.55), transparent 30%),
    radial-gradient(circle at 78% 28%, rgba(221, 241, 236, 0.72), transparent 34%),
    linear-gradient(145deg, rgba(255, 255, 255, 0.72), rgba(247, 253, 251, 0.86));
}

.course-stage svg {
  width: min(100%, 760px);
  max-height: 430px;
}

.manipulative {
  width: min(100%, 720px);
  min-height: 340px;
  display: grid;
  place-items: center;
}

.block-grid,
.array-board,
.percent-board {
  display: grid;
  gap: 8px;
  align-content: center;
  justify-content: center;
}

.block-grid {
  width: min(100%, var(--board-width, 280px));
  grid-template-columns: repeat(var(--columns, 5), minmax(0, 46px)) !important;
}

.touch-block,
.array-cell,
.percent-cell {
  display: grid;
  place-items: center;
  border: 2px solid #2d73d6;
  border-radius: 7px;
  background: linear-gradient(145deg, #ffffff, #dfeaff);
  box-shadow: 0 8px 18px rgba(45, 115, 214, 0.12);
  color: #17384a;
  font-weight: 800;
}

.touch-block {
  width: 100%;
  height: auto;
  aspect-ratio: 1;
  min-width: 0;
}

.array-cell {
  width: 34px;
  height: 34px;
}

.percent-board {
  grid-template-columns: repeat(10, 22px);
  gap: 3px;
}

.percent-cell {
  width: 22px;
  height: 22px;
  border-width: 1px;
  border-color: rgba(45, 115, 214, 0.28);
  box-shadow: none;
}

.percent-cell.is-active {
  border-color: #287b73;
  background: #83cfc2;
}

.fraction-board {
  display: grid;
  width: min(620px, 100%);
  gap: 12px;
}

.fraction-row {
  display: grid;
  grid-template-columns: repeat(var(--parts, 2), 1fr);
  min-height: 88px;
  overflow: hidden;
  border: 2px solid #17384a;
  border-radius: 8px;
  background: #fff;
}

.fraction-part {
  border-right: 1px solid rgba(23, 56, 74, 0.35);
  background: #fff;
}

.fraction-part:last-child { border-right: 0; }
.fraction-part.is-active { background: #83cfc2; }

.bar-board {
  width: min(620px, 100%);
  display: grid;
  gap: 18px;
}

.quantity-bar {
  display: grid;
  place-items: center;
  min-height: 54px;
  border: 2px solid #2d73d6;
  border-radius: 8px;
  background: linear-gradient(90deg, #e6f0ff, #c9e5df);
  color: #17384a;
  font-weight: 800;
}

.model-caption {
  margin: 16px 0 0;
  color: #3c5b67;
  font-weight: 700;
  text-align: center;
}

.expression-lab {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  width: min(100%, 780px);
  min-height: 390px;
}

.expression-workbench {
  border: 1px solid rgba(38, 112, 109, 0.16);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.7);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.88);
}

.expression-workbench {
  display: grid;
  grid-template-rows: auto auto auto auto 1fr auto;
  gap: 12px;
  min-width: 0;
  padding: 18px;
  background:
    radial-gradient(circle at 18% 10%, rgba(255, 255, 255, 0.92), transparent 34%),
    radial-gradient(circle at 84% 72%, rgba(203, 229, 223, 0.42), transparent 38%),
    linear-gradient(145deg, rgba(250, 254, 255, 0.94), rgba(237, 248, 245, 0.9));
}

.expression-canvas {
  min-height: 390px;
}

.expression-scene {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 150px;
  gap: 14px;
  min-height: 218px;
  border: 1px solid rgba(45, 115, 214, 0.1);
  border-radius: 8px;
  background:
    linear-gradient(rgba(45, 115, 214, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(45, 115, 214, 0.045) 1px, transparent 1px),
    linear-gradient(145deg, rgba(255, 255, 255, 0.78), rgba(245, 251, 249, 0.92));
  background-size: auto, auto, 26px 26px, 26px 26px, auto;
  padding: 14px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.82), 0 14px 34px rgba(37, 55, 78, 0.08);
}

.direct-drag-hint {
  position: absolute;
  right: 176px;
  top: 18px;
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1px solid rgba(45, 115, 214, 0.16);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.82);
  padding: 7px 10px;
  color: #287b73;
  font-size: 12px;
  font-weight: 900;
  pointer-events: none;
  box-shadow: 0 12px 28px rgba(37, 55, 78, 0.08);
}

.direct-drag-hint i {
  width: 34px;
  height: 10px;
  border-bottom: 2px solid rgba(40, 123, 115, 0.72);
  border-right: 2px solid rgba(40, 123, 115, 0.72);
  transform: skewX(-28deg);
}

.expression-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: #55706f;
  font-size: 12px;
  font-weight: 800;
}

.expression-head strong {
  color: #17384a;
  font-size: 28px;
  line-height: 1;
}

.expression-word-card {
  display: grid;
  grid-template-columns: auto auto auto minmax(0, 1fr);
  gap: 8px;
  align-items: center;
  border: 1px solid rgba(40, 123, 115, 0.16);
  border-radius: 8px;
  background:
    radial-gradient(circle at 8% 0%, rgba(255, 255, 255, 0.95), transparent 42%),
    linear-gradient(135deg, rgba(246, 253, 250, 0.94), rgba(237, 246, 255, 0.88));
  padding: 10px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9), 0 12px 30px rgba(37, 55, 78, 0.06);
}

.expression-word-card span,
.expression-word-card i,
.expression-word-card em,
.expression-action-chip {
  display: grid;
  min-height: 34px;
  place-items: center;
  border-radius: 8px;
  padding: 0 12px;
  appearance: none;
  font-size: 14px;
  font-style: normal;
  font-weight: 900;
}

.expression-word-card span {
  border: 1px solid rgba(45, 115, 214, 0.18);
  background: #edf6ff;
  color: #155bc5;
}

.expression-word-card i,
.expression-action-chip.is-times {
  border: 1px solid rgba(40, 123, 115, 0.2);
  background: #e8f7ef;
  color: #287b73;
}

.expression-word-card em,
.expression-action-chip.is-minus {
  border: 1px solid rgba(211, 107, 98, 0.2);
  background: #fff0ee;
  color: #b64a55;
}

.expression-action-chip {
  cursor: grab;
  box-shadow: 0 8px 18px rgba(37, 55, 78, 0.08);
  transition: transform 140ms ease, box-shadow 140ms ease, border-color 140ms ease;
  touch-action: none;
  user-select: none;
}

.expression-action-chip:hover,
.expression-action-chip:focus-visible {
  border-color: rgba(45, 115, 214, 0.36);
  box-shadow: 0 14px 26px rgba(37, 55, 78, 0.12);
  transform: translateY(-1px);
  outline: none;
}

.expression-action-chip.is-dragging-source {
  cursor: grabbing;
  opacity: 0.6;
  transform: scale(0.98);
}

.expression-word-card b {
  min-width: 0;
  color: #3c5b67;
  font-size: 13px;
  font-weight: 780;
  line-height: 1.35;
}

.expression-reading {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.expression-reading span {
  display: grid;
  gap: 4px;
  border: 1px solid rgba(45, 115, 214, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  padding: 9px 10px;
  box-shadow: 0 8px 18px rgba(37, 55, 78, 0.06);
}

.expression-reading b {
  color: #607784;
  font-size: 11px;
  font-weight: 850;
}

.expression-reading em {
  color: #17384a;
  font-size: 18px;
  font-style: normal;
  font-weight: 900;
}

.expression-dropzone {
  position: relative;
  display: flex;
  align-content: center;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  min-height: 218px;
  border: 2px dashed rgba(45, 115, 214, 0.22);
  border-radius: 8px;
  background:
    radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.86), transparent 45%),
    rgba(247, 251, 255, 0.78);
  padding: 20px;
  transition: border-color 140ms ease, background-color 140ms ease, box-shadow 140ms ease;
}

.dropzone-label {
  position: absolute;
  top: 10px;
  left: 12px;
  color: #607784;
  font-size: 12px;
  font-weight: 900;
  pointer-events: none;
}

.expression-dropzone.is-drop-target {
  border-color: #2d73d6;
  background-color: rgba(229, 240, 255, 0.95);
  box-shadow: inset 0 0 0 3px rgba(45, 115, 214, 0.09), 0 22px 48px rgba(45, 115, 214, 0.16);
  transform: translateY(-1px);
}

.expression-task {
  margin: 0;
  color: #607784;
  font-size: 13px;
  font-weight: 760;
  line-height: 1.45;
}

.expression-invariant {
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1px solid rgba(40, 123, 115, 0.14);
  border-radius: 8px;
  background: rgba(247, 253, 251, 0.82);
  padding: 9px 11px;
  color: #3c5b67;
  font-size: 13px;
  font-weight: 760;
}

.expression-invariant b {
  color: #287b73;
  font-size: 12px;
  font-weight: 900;
}

.expression-empty {
  color: #7b8e94;
  font-size: 14px;
  font-weight: 700;
  pointer-events: none;
}

.expression-palette {
  display: grid;
  align-content: start;
  gap: 12px;
  border: 1px solid rgba(38, 112, 109, 0.16);
  border-radius: 8px;
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.86), rgba(244, 250, 248, 0.78));
  padding: 14px;
  transition: border-color 140ms ease, background-color 140ms ease, box-shadow 140ms ease;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9);
}

.expression-palette.is-drop-target {
  border-color: #d36b62;
  background: rgba(255, 239, 237, 0.92);
  box-shadow: inset 0 0 0 3px rgba(211, 107, 98, 0.09), 0 18px 38px rgba(211, 107, 98, 0.12);
  transform: translateY(-1px);
}

.palette-label,
.palette-note {
  color: #55706f;
  font-size: 12px;
  font-weight: 800;
}

.palette-note {
  color: #7b8e94;
  font-weight: 650;
}

.palette-tiles {
  display: grid;
  grid-template-columns: 1fr;
  gap: 9px;
}

.expression-tile {
  display: grid;
  place-items: center;
  height: 54px;
  min-width: 54px;
  border: 2px solid #2d73d6;
  border-radius: 8px;
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.95), rgba(223, 234, 255, 0.98));
  box-shadow: 0 10px 22px rgba(45, 115, 214, 0.15), inset 0 1px 0 rgba(255, 255, 255, 0.9), inset 0 -10px 16px rgba(45, 115, 214, 0.08);
  color: #17384a;
  font-size: 20px;
  font-weight: 850;
  cursor: grab;
  touch-action: none;
  user-select: none;
  transition: transform 140ms ease, box-shadow 140ms ease, opacity 140ms ease;
}

.expression-tile:hover,
.expression-tile:focus-visible {
  box-shadow: 0 14px 26px rgba(45, 115, 214, 0.18), inset 0 1px 0 rgba(255, 255, 255, 0.95);
  outline: none;
  transform: translateY(-2px);
}

.expression-dropzone .expression-tile {
  min-width: 62px;
  animation: tile-pop 180ms ease-out;
}

.balance-handle {
  cursor: grab;
  outline: none;
  touch-action: none;
}

.balance-handle rect[fill="transparent"] {
  opacity: 0.82;
  transition: stroke 140ms ease, opacity 140ms ease, filter 140ms ease, fill 140ms ease;
}

.balance-handle:hover rect[fill="transparent"],
.balance-handle:focus-visible rect[fill="transparent"] {
  opacity: 1;
  fill: rgba(31, 111, 229, 0.05);
  stroke: rgba(31, 111, 229, 0.62);
  filter: drop-shadow(0 10px 18px rgba(31, 111, 229, 0.16));
}

.balance-handle.is-dragging-source {
  cursor: grabbing;
}

.balance-handle.is-dragging-source rect[fill="transparent"] {
  fill: rgba(40, 123, 115, 0.08);
  stroke: rgba(40, 123, 115, 0.76);
  filter: drop-shadow(0 14px 20px rgba(40, 123, 115, 0.22));
}

.balance-handle:active {
  cursor: grabbing;
}

.balance-handle text {
  pointer-events: none;
}

.balance-x-tile,
.balance-unit-tile,
.balance-result-group {
  transition: transform 150ms ease, filter 150ms ease;
}

.balance-handle:hover .balance-x-tile,
.balance-handle:focus-visible .balance-x-tile,
.balance-handle:hover .balance-unit-tile,
.balance-handle:focus-visible .balance-unit-tile,
.balance-handle:hover.balance-result-group,
.balance-handle:focus-visible.balance-result-group {
  filter: drop-shadow(0 12px 16px rgba(31, 111, 229, 0.18));
}

.balance-handle:hover .balance-x-tile,
.balance-handle:focus-visible .balance-x-tile {
  transform: translateY(-3px);
}

.balance-handle:hover .balance-unit-tile,
.balance-handle:focus-visible .balance-unit-tile {
  transform: translateY(-2px);
}

.balance-handle.is-dragging-source .balance-x-tile,
.balance-handle.is-dragging-source .balance-unit-tile,
.balance-handle.is-dragging-source.balance-result-group {
  filter: drop-shadow(0 15px 20px rgba(40, 123, 115, 0.24));
  transform: translateY(-4px) scale(1.015);
}

.balance-pan-labels text,
.balance-drag-labels text {
  paint-order: stroke;
  stroke: rgba(255, 255, 255, 0.8);
  stroke-width: 3px;
  stroke-linejoin: round;
}

.balance-equation-title,
.balance-result-text {
  display: none;
}

.balance-step-panel {
  display: flex;
  width: min(100%, 720px);
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin: -8px auto 12px;
  border: 1px solid rgba(31, 111, 229, 0.14);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 12px 28px rgba(35, 63, 102, 0.1);
  padding: 8px 10px;
}

.balance-step-panel button {
  min-height: 36px;
  border: 0;
  border-radius: 999px;
  background: #1f6fe5;
  padding: 0 16px;
  color: #ffffff;
  cursor: pointer;
  font-size: 13px;
  font-weight: 900;
  box-shadow: 0 12px 24px rgba(31, 111, 229, 0.2);
}

.balance-step-panel button:hover,
.balance-step-panel button:focus-visible {
  background: #155bc5;
  outline: none;
  transform: translateY(-1px);
}

.balance-step-panel span {
  color: #607080;
  font-size: 12px;
  font-weight: 820;
}

.area-drag-model {
  touch-action: none;
}

.area-drag-handle {
  cursor: grab;
  outline: none;
  touch-action: none;
}

.area-drag-handle circle,
.area-drag-handle line {
  transition: filter 140ms ease, stroke 140ms ease, transform 140ms ease;
}

.area-drag-handle:hover circle,
.area-drag-handle:focus-visible circle,
.area-drag-handle.is-dragging-source circle {
  filter: drop-shadow(0 12px 18px rgba(40, 123, 115, 0.22));
}

.area-drag-handle.is-dragging-source {
  cursor: grabbing;
}

.course-stage.is-distributive-stage {
  overflow: hidden !important;
  touch-action: none;
}

.course-stage.is-distributive-stage .distributive-direct-model,
.course-stage.is-distributive-stage .distributive-drag-handle {
  touch-action: none;
}

.number-line-direct {
  touch-action: none;
}

.number-insight-model {
  touch-action: none;
}

.number-insight-handle {
  cursor: grab;
  outline: none;
  touch-action: none;
}

.number-insight-handle circle,
.number-insight-handle rect,
.number-insight-handle text {
  transition: filter 140ms ease, transform 140ms ease;
}

.number-insight-handle:hover circle,
.number-insight-handle:focus-visible circle,
.number-insight-handle.is-dragging-source circle {
  filter: drop-shadow(0 14px 18px rgba(45, 115, 214, 0.22));
}

.number-insight-handle.is-dragging-source {
  cursor: grabbing;
}

.sign-toggle,
.order-layer,
.variable-value-chip,
.term-pick-card,
.like-family-tray {
  cursor: pointer;
  outline: none;
}

.sign-toggle rect,
.order-layer rect,
.variable-value-chip rect,
.term-pick-card rect,
.like-family-tray rect {
  transition: filter 140ms ease, transform 140ms ease;
}

.sign-toggle:hover rect,
.sign-toggle:focus-visible rect,
.order-layer:hover rect,
.order-layer:focus-visible rect,
.order-layer.is-active rect,
.variable-value-chip:hover rect,
.variable-value-chip:focus-visible rect,
.variable-value-chip.is-active rect,
.term-pick-card:hover rect,
.term-pick-card:focus-visible rect,
.term-pick-card.is-active rect,
.like-family-tray:hover rect,
.like-family-tray:focus-visible rect,
.like-family-tray.is-active rect {
  filter: drop-shadow(0 14px 18px rgba(45, 115, 214, 0.18));
}

.term-pick-card:hover,
.term-pick-card:focus-visible,
.like-family-tray:hover,
.like-family-tray:focus-visible,
.variable-value-chip:hover,
.variable-value-chip:focus-visible {
  transform: translateY(-1px);
}

.svg-hit-button {
  width: 100%;
  height: 100%;
  display: block;
  border: 0;
  padding: 0;
  margin: 0;
  background: transparent;
  color: transparent;
  cursor: pointer;
}

.algebra-html-model {
  box-sizing: border-box;
  width: min(720px, 100%);
  height: 310px;
  min-height: 0;
  margin: auto;
  border: 1px solid rgba(69, 102, 116, 0.16);
  border-radius: 28px;
  background: rgba(251, 253, 251, 0.94);
  box-shadow: 0 16px 34px rgba(35, 63, 102, 0.08);
  padding: 28px 34px 24px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 12px;
}

.algebra-html-model h3,
.algebra-html-model p {
  margin: 0;
  text-align: center;
}

.algebra-html-model h3 {
  color: #17384a;
  font-size: 23px;
  line-height: 1.15;
  font-weight: 950;
}

.algebra-html-model p {
  color: #55706f;
  font-size: 16px;
  font-weight: 900;
}

.term-card-row,
.like-tray-row,
.term-structure-grid {
  display: grid;
  gap: 16px;
}

.term-card-row,
.like-tray-row {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.term-html-card,
.like-html-tray,
.package-card,
.poly-tray,
.term-structure-grid div {
  border: 2px solid rgba(69, 102, 116, 0.14);
  border-radius: 20px;
  background: #fff;
  box-shadow: 0 10px 22px rgba(35, 63, 102, 0.06);
}

.term-html-card,
.like-html-tray,
.package-card,
.poly-tray {
  min-height: 82px;
  padding: 10px 10px;
  cursor: pointer;
  color: #17384a;
  transition: transform 140ms ease, box-shadow 140ms ease, border-color 140ms ease;
}

.term-html-card:hover,
.term-html-card:focus-visible,
.term-html-card.is-active,
.like-html-tray:hover,
.like-html-tray:focus-visible,
.like-html-tray.is-active,
.package-card:hover,
.package-card:focus-visible,
.package-card.is-active,
.poly-tray:hover,
.poly-tray:focus-visible,
.poly-tray.is-active {
  transform: translateY(-1px);
  border-color: #2d73d6;
  box-shadow: 0 16px 28px rgba(45, 115, 214, 0.15);
}

.term-html-card strong,
.term-html-card span,
.like-html-tray span,
.like-html-tray strong,
.package-card span,
.package-card strong,
.package-card i,
.poly-tray span,
.poly-tray i,
.poly-tray strong {
  display: block;
}

.term-html-card strong {
  font-size: 25px;
  font-weight: 950;
}

.term-html-card span,
.like-html-tray span {
  margin-top: 8px;
  color: #55706f;
  font-size: 14px;
  font-weight: 900;
}

.term-structure-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.term-structure-grid div {
  padding: 12px 10px;
  text-align: center;
}

.term-structure-grid span {
  display: block;
  color: #55706f;
  font-size: 12px;
  font-weight: 900;
}

.term-structure-grid strong {
  display: block;
  margin-top: 5px;
  color: #17384a;
  font-size: 16px;
  font-weight: 950;
}

.like-html-tray i {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  margin: 7px auto;
  max-width: 126px;
  font-style: normal;
}

.like-html-tray i b {
  min-height: 27px;
  border: 1.5px solid rgba(45, 115, 214, 0.52);
  border-radius: 9px;
  background: rgba(255, 255, 255, 0.82);
  display: grid;
  place-items: center;
  font-size: 13px;
  font-weight: 950;
}

.like-html-tray strong {
  font-size: 20px;
  font-weight: 950;
}

.package-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.package-card {
  min-height: 94px;
  color: #17384a;
  background: linear-gradient(180deg, #ffffff, #f7fbff);
}

.package-card.is-flip {
  background: linear-gradient(180deg, #fff8f5, #ffece8);
}

.package-card span,
.poly-tray span {
  color: #55706f;
  font-size: 13px;
  font-weight: 900;
}

.package-card strong {
  margin-top: 8px;
  color: #17384a;
  font-size: 23px;
  font-weight: 950;
}

.package-card i {
  margin-top: 7px;
  color: #55706f;
  font-size: 12px;
  font-style: normal;
  font-weight: 850;
}

.poly-tray-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.bracket-area-model .poly-tray-row {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.poly-tray {
  min-height: 72px;
  color: #17384a;
  background: #fff;
}

.poly-tray i {
  margin-top: 5px;
  color: #55706f;
  font-size: 13px;
  font-style: normal;
  font-weight: 900;
}

.poly-tray strong {
  margin-top: 5px;
  color: #17384a;
  font-size: 20px;
  font-weight: 950;
}

.like-result {
  text-align: center;
  color: #17384a;
  font-size: 20px;
  font-weight: 950;
}

.like-result span {
  display: block;
  margin-top: 4px;
  color: #55706f;
  font-size: 14px;
  font-weight: 900;
}

.bracket-area-model,
.polynomial-subtract-model {
  gap: 8px;
  padding-top: 20px;
  padding-bottom: 16px;
}

.bracket-area-model h3,
.polynomial-subtract-model h3 {
  font-size: 21px;
}

.bracket-area-model .package-card,
.polynomial-subtract-model .package-card {
  min-height: 78px;
}

.bracket-area-model .poly-tray,
.polynomial-subtract-model .poly-tray {
  min-height: 62px;
}

.bracket-area-model .like-result,
.polynomial-subtract-model .like-result {
  font-size: 18px;
}

.bracket-area-model .like-result span,
.polynomial-subtract-model .like-result span {
  font-size: 12px;
}

@media (max-width: 640px) {
  .algebra-html-model {
    height: auto;
    min-height: 250px;
    padding: 20px 18px;
    gap: 12px;
  }

  .algebra-html-model h3 {
    font-size: 18px;
  }

  .term-card-row,
  .like-tray-row,
  .term-structure-grid {
    gap: 8px;
  }

  .term-html-card,
  .like-html-tray,
  .package-card,
  .poly-tray {
    min-height: 76px;
    padding: 10px 6px;
  }

  .term-html-card strong {
    font-size: 18px;
  }

  .term-html-card span,
  .like-html-tray span,
  .like-result span {
    font-size: 11px;
  }

  .term-structure-grid div {
    padding: 8px 5px;
  }

  .term-structure-grid strong {
    font-size: 12px;
  }

  .like-html-tray i {
    grid-template-columns: repeat(2, 1fr);
    gap: 4px;
  }

  .like-html-tray i b {
    min-height: 21px;
    font-size: 10px;
  }

  .like-result {
    font-size: 16px;
  }

  .package-row,
  .poly-tray-row,
  .bracket-area-model .poly-tray-row {
    gap: 8px;
  }

  .package-card strong {
    font-size: 16px;
  }

  .package-card i,
  .package-card span,
  .poly-tray span,
  .poly-tray i {
    font-size: 10px;
  }

  .poly-tray strong {
    font-size: 14px;
  }
}

.number-line-handle {
  cursor: grab;
  outline: none;
  touch-action: none;
}

.number-line-handle circle,
.number-line-handle text {
  transition: filter 140ms ease, transform 140ms ease;
}

.number-line-handle:hover circle,
.number-line-handle:focus-visible circle,
.number-line-handle.is-dragging-source circle {
  filter: drop-shadow(0 12px 18px rgba(40, 123, 115, 0.22));
}

.number-line-handle.is-dragging-source {
  cursor: grabbing;
}

.equation-responsive-board {
  width: min(100%, 760px);
  display: grid;
  place-items: center;
}

.desktop-equation-balance {
  width: 100%;
}

.mobile-equation-balance {
  display: none;
}

.expression-tile.is-variable {
  width: 78px;
}

.expression-tile.is-unit {
  width: 54px;
}

.expression-tile.is-negative {
  border-color: #d36b62;
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.96), rgba(255, 226, 222, 0.98));
  color: #8f3e38;
}

.expression-tile:active,
.expression-tile.is-dragging-source {
  cursor: grabbing;
  opacity: 0.38;
  transform: scale(0.96);
}

.expression-drag-ghost {
  position: fixed;
  z-index: 1000;
  margin: 0;
  pointer-events: none;
  opacity: 0.96;
  transform-origin: top left;
  will-change: transform;
  box-shadow: 0 20px 42px rgba(37, 55, 78, 0.22);
}

/* Algebra-tile model polish: turn the expression builder into a tangible desk. */
.expression-main-canvas .expression-workbench {
  border-color: rgba(64, 111, 178, 0.16);
  background:
    radial-gradient(circle at 12% 8%, rgba(255, 255, 255, 0.98), transparent 34%),
    radial-gradient(circle at 88% 70%, rgba(221, 245, 237, 0.5), transparent 38%),
    linear-gradient(145deg, rgba(255, 255, 255, 0.94), rgba(238, 248, 255, 0.9));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.94),
    0 16px 34px rgba(38, 77, 130, 0.08);
}

.expression-main-canvas .expression-head {
  min-height: 38px;
  border: 1px solid rgba(31, 111, 229, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  padding: 6px 10px;
}

.expression-main-canvas .expression-head strong {
  display: inline-grid;
  min-width: 88px;
  min-height: 28px;
  place-items: center;
  border-radius: 999px;
  background: linear-gradient(180deg, #edf6ff, #dfeaff);
  color: #155bc5;
  font-size: 22px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.96);
}

.expression-main-canvas .expression-word-card {
  position: relative;
  overflow: hidden;
  border-color: rgba(64, 111, 178, 0.14);
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.74)),
    linear-gradient(135deg, #f7fbff, #edf8f3);
}

.expression-main-canvas .expression-word-card::before {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  top: 50%;
  height: 2px;
  background: linear-gradient(90deg, rgba(31, 111, 229, 0.14), rgba(42, 166, 120, 0.16), rgba(211, 107, 98, 0.16));
  transform: translateY(-50%);
  pointer-events: none;
}

.expression-main-canvas .expression-word-card > * {
  position: relative;
  z-index: 1;
}

.expression-main-canvas .expression-word-card span,
.expression-main-canvas .expression-action-chip {
  border-radius: 999px;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.96),
    0 10px 18px rgba(38, 77, 130, 0.08);
}

.expression-main-canvas .expression-action-chip::after {
  content: "";
  width: 22px;
  height: 4px;
  margin-top: 2px;
  border-radius: 999px;
  background: currentColor;
  opacity: 0.22;
}

.expression-main-canvas .expression-reading span {
  min-height: 46px;
  background:
    radial-gradient(circle at 18% 8%, rgba(255, 255, 255, 0.96), transparent 36%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.88), rgba(239, 247, 255, 0.78));
}

.expression-main-canvas .expression-scene {
  border-color: rgba(64, 111, 178, 0.14);
  background:
    linear-gradient(rgba(31, 111, 229, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 111, 229, 0.05) 1px, transparent 1px),
    radial-gradient(circle at 30% 20%, rgba(255, 255, 255, 0.96), transparent 32%),
    linear-gradient(180deg, #f7fbff, #edf6ff);
  background-size: 24px 24px, 24px 24px, auto, auto;
}

.expression-main-canvas .expression-dropzone {
  align-content: center;
  justify-content: flex-start;
  border: 2px solid rgba(31, 111, 229, 0.18);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(247, 251, 255, 0.82));
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.8),
    inset 0 -16px 28px rgba(31, 111, 229, 0.04),
    0 14px 28px rgba(38, 77, 130, 0.08);
}

.expression-main-canvas .expression-dropzone::after {
  content: "3x - 5";
  position: absolute;
  right: 16px;
  bottom: 12px;
  color: rgba(23, 56, 74, 0.08);
  font-size: 46px;
  font-weight: 950;
  letter-spacing: 0;
  pointer-events: none;
}

.expression-main-canvas .dropzone-label {
  border: 1px solid rgba(31, 111, 229, 0.12);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.86);
  padding: 4px 9px;
  color: #155bc5;
}

.expression-main-canvas .expression-empty {
  display: grid;
  min-height: 70px;
  width: min(100%, 430px);
  place-items: center;
  border: 1px dashed rgba(31, 111, 229, 0.24);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  color: #607784;
}

.expression-main-canvas .expression-palette {
  border-color: rgba(64, 111, 178, 0.14);
  background:
    radial-gradient(circle at 24% 8%, rgba(255, 255, 255, 0.96), transparent 34%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.9), rgba(239, 247, 255, 0.78));
}

.expression-main-canvas .expression-tile {
  position: relative;
  border-radius: 10px;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.96),
    inset 0 -10px 18px rgba(31, 111, 229, 0.08),
    0 12px 20px rgba(38, 77, 130, 0.12);
}

.expression-main-canvas .expression-tile::before {
  content: "";
  position: absolute;
  left: 8px;
  right: 8px;
  top: 7px;
  height: 3px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.8);
  pointer-events: none;
}

.expression-main-canvas .expression-tile.is-variable {
  min-width: 74px;
  background:
    linear-gradient(145deg, #ffffff, #dfeaff 62%, #c6d9ff);
}

.expression-main-canvas .expression-tile.is-unit:not(.is-negative) {
  background:
    linear-gradient(145deg, #ffffff, #d8eee7 62%, #bde4d6);
  border-color: #2aa678;
}

.expression-main-canvas .expression-tile.is-negative {
  background:
    linear-gradient(145deg, #ffffff, #ffe2de 62%, #ffc9c3);
}

.expression-main-canvas .expression-dropzone .expression-tile {
  transform: translateY(-2px);
}

@media (min-width: 1181px) {
  .lesson-studio .visual-stage .expression-main-canvas .expression-empty {
    min-height: 42px;
    width: min(100%, 360px);
    font-size: 12px;
  }

  .lesson-studio .visual-stage .expression-main-canvas .expression-dropzone::after {
    right: 10px;
    bottom: 7px;
    font-size: 30px;
  }

  .lesson-studio .visual-stage .expression-main-canvas .expression-head {
    min-height: 26px;
    padding: 3px 6px;
  }

  .lesson-studio .visual-stage .expression-main-canvas .expression-head strong {
    min-height: 22px;
    font-size: 16px;
  }

  .lesson-studio .visual-stage .expression-main-canvas .expression-reading span {
    min-height: 0;
  }
}

.expression-drag-ghost.is-action-ghost {
  display: grid;
  place-items: center;
  border-radius: 8px;
  font-weight: 900;
}

@keyframes tile-pop {
  from { transform: scale(0.92); opacity: 0.72; }
  to { transform: scale(1); opacity: 1; }
}

.machine-flow {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 18px;
  width: 100%;
  font-size: 26px;
  font-weight: 800;
}

.machine-flow .touch-block {
  width: 58px;
}

.practice-card .answer-options {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 10px;
}

.practice-card {
  display: grid;
  gap: 10px;
}

.practice-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.practice-card-head span,
.practice-card-head em,
.practice-question small {
  display: inline-flex;
  min-height: 24px;
  align-items: center;
  border-radius: 999px;
  padding: 0 8px;
  font-size: 11px;
  font-style: normal;
  font-weight: 850;
}

.practice-card-head span {
  background: #edf6ff;
  color: #155bc5;
}

.practice-card-head em {
  background: #e8f7ef;
  color: #287b73;
}

.practice-question {
  display: grid;
  gap: 6px;
}

.practice-question strong {
  color: #17384a;
  font-size: 15px;
  line-height: 1.32;
  font-weight: 880;
}

.practice-question span {
  color: #4d6477;
  font-size: 12px;
  font-weight: 760;
}

.practice-question small {
  width: fit-content;
  background: rgba(240, 164, 56, 0.13);
  color: #9a5a12;
}

.answer-options button {
  flex: 1;
  min-width: 72px;
  min-height: 40px;
  overflow: visible;
  overflow-wrap: anywhere;
  line-height: 1.22;
  white-space: normal;
}

.practice-diagnosis {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 8px;
  min-height: 42px;
  border: 1px solid rgba(48, 75, 116, 0.12);
  border-radius: 8px;
  background: rgba(247, 251, 255, 0.78);
  padding: 8px 10px;
  color: #4d6477;
  font-size: 12px;
  font-weight: 740;
}

.practice-diagnosis b {
  color: #607080;
  font-size: 11px;
  font-weight: 900;
}

.practice-diagnosis span {
  min-width: 0;
}

.practice-diagnosis a {
  border-radius: 7px;
  background: rgba(31, 111, 229, 0.08);
  padding: 6px 8px;
  color: #155bc5;
  font-size: 11px;
  font-weight: 900;
  text-decoration: none;
}

.practice-diagnosis.right {
  border-color: rgba(42, 166, 120, 0.22);
  background: rgba(232, 247, 239, 0.76);
}

.practice-diagnosis.right b {
  color: #287b73;
}

.practice-diagnosis.wrong {
  border-color: rgba(211, 107, 98, 0.22);
  background: rgba(255, 239, 237, 0.82);
}

.practice-diagnosis.wrong b {
  color: #b64a55;
}

.complete-button {
  width: 100%;
  min-height: 50px;
  background: linear-gradient(135deg, #2d73d6, #3c9b8f);
  color: #fff;
  font-weight: 750;
}

.complete-button.is-complete {
  background: #d8eee7;
  color: #24504f;
}

.complete-button.is-disabled,
.complete-button:disabled {
  border-color: rgba(170, 182, 198, 0.24);
  background: #eef3f7;
  color: #7b8e94;
  cursor: not-allowed;
  box-shadow: none;
}

.completion-evidence {
  display: grid;
  gap: 6px;
  border: 1px solid rgba(31, 111, 229, 0.12);
  border-radius: 8px;
  background: rgba(247, 251, 255, 0.82);
  padding: 10px;
  color: #4d6477;
}

.completion-evidence b {
  color: #155bc5;
  font-size: 12px;
  font-weight: 900;
}

.completion-evidence span {
  font-size: 12px;
  font-weight: 740;
  line-height: 1.42;
}

.completion-evidence a {
  display: grid;
  width: fit-content;
  min-height: 30px;
  place-items: center;
  border-radius: 7px;
  background: rgba(31, 111, 229, 0.08);
  color: #155bc5;
  font-size: 11px;
  font-weight: 900;
  padding: 0 9px;
  text-decoration: none;
}

.after-class-routes {
  display: grid;
  gap: 7px;
}

.after-class-routes a {
  display: grid;
  width: 100%;
  min-height: 54px;
  place-items: stretch;
  gap: 3px;
  border: 1px solid rgba(42, 166, 120, 0.16);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  padding: 9px 10px;
  color: #17384a;
  text-decoration: none;
}

.after-class-routes a:hover,
.after-class-routes a:focus-visible {
  border-color: rgba(42, 166, 120, 0.34);
  background: #f7fffb;
  outline: none;
  transform: translateY(-1px);
}

.after-class-routes strong {
  color: #287b73;
  font-size: 13px;
  font-weight: 920;
}

.after-class-routes small {
  color: #607080;
  font-size: 11px;
  font-weight: 760;
  line-height: 1.3;
}

.evidence-checklist {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.evidence-checklist i {
  display: inline-flex;
  min-height: 24px;
  align-items: center;
  border-radius: 999px;
  background: rgba(170, 182, 198, 0.14);
  color: #607080;
  font-size: 11px;
  font-style: normal;
  font-weight: 850;
  padding: 0 8px;
}

.evidence-checklist i.is-done {
  background: rgba(42, 166, 120, 0.12);
  color: #287b73;
}

.completion-evidence.is-complete {
  border-color: rgba(42, 166, 120, 0.22);
  background: rgba(232, 247, 239, 0.78);
}

.completion-evidence.is-complete b {
  color: #287b73;
}

.completion-evidence.is-draft {
  border-color: rgba(240, 169, 79, 0.24);
  background: rgba(255, 249, 236, 0.84);
}

.completion-evidence.is-draft b {
  color: #9a5a12;
}

.catalog-dialog {
  width: min(920px, calc(100% - 28px));
  max-height: calc(100vh - 40px);
  border: 1px solid rgba(38, 112, 109, 0.18);
  border-radius: 8px;
  background: rgba(244, 251, 248, 0.97);
  box-shadow: 0 36px 120px rgba(25, 58, 72, 0.24);
  padding: 20px;
}

.catalog-dialog::backdrop {
  background: rgba(23, 56, 74, 0.28);
  backdrop-filter: blur(8px);
}

.catalog-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.catalog-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.catalog-actions a {
  display: grid;
  min-height: 36px;
  place-items: center;
  border: 1px solid rgba(45, 115, 214, 0.14);
  border-radius: 8px;
  background: rgba(237, 246, 255, 0.82);
  color: #155bc5;
  font-size: 12px;
  font-weight: 900;
  padding: 0 11px;
  text-decoration: none;
}

.catalog-actions a:hover,
.catalog-actions a:focus-visible {
  border-color: rgba(45, 115, 214, 0.28);
  background: #e8f1ff;
  outline: none;
}

.catalog-search {
  display: grid;
  gap: 6px;
  margin: 16px 0 12px;
  color: #55706f;
  font-size: 12px;
  font-weight: 700;
}

.catalog-search input {
  min-height: 44px;
  border: 1px solid rgba(38, 112, 109, 0.18);
  border-radius: 8px;
  background: #fff;
  padding: 0 13px;
}

.grade-tabs {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 8px;
}

.grade-tabs button {
  flex: 0 0 auto;
  border: 1px solid rgba(38, 112, 109, 0.16);
  border-radius: 8px;
  background: #fff;
  padding: 8px 12px;
  cursor: pointer;
}

.grade-tabs button.is-active {
  background: #cde9e3;
  color: #24504f;
}

.catalog-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  max-height: 56vh;
  overflow: auto;
  padding: 4px;
}

.lesson-link {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: start;
  gap: 10px;
  border: 1px solid rgba(38, 112, 109, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.74);
  padding: 12px;
  color: #17384a;
  text-align: left;
  cursor: pointer;
  transition: transform 140ms ease, border-color 140ms ease, box-shadow 140ms ease, background 140ms ease;
}

.lesson-link:hover,
.lesson-link:focus-visible {
  transform: translateY(-1px);
  border-color: rgba(31, 111, 229, 0.32);
  box-shadow: 0 12px 26px rgba(35, 63, 102, 0.1);
  outline: none;
}

.lesson-link small {
  display: grid;
  min-width: 54px;
  min-height: 28px;
  place-items: center;
  border-radius: 7px;
  background: rgba(31, 111, 229, 0.08);
  color: #155bc5;
  font-size: 11px;
  font-weight: 900;
}

.lesson-link span {
  display: grid;
  min-width: 0;
  gap: 4px;
}

.lesson-link strong {
  overflow: hidden;
  color: #17384a;
  font-size: 14px;
  font-weight: 880;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-link em {
  overflow: hidden;
  color: #607080;
  font-size: 11px;
  font-style: normal;
  font-weight: 740;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-link b {
  border-radius: 999px;
  background: rgba(170, 182, 198, 0.14);
  padding: 4px 7px;
  color: #607080;
  font-size: 10px;
  font-weight: 900;
  white-space: nowrap;
}

.lesson-link.is-current {
  border-color: #2d73d6;
  background: #e8f1ff;
}

.lesson-link.is-ready b {
  background: #edf6ff;
  color: #155bc5;
}

.lesson-link.is-reviewed {
  border-color: rgba(106, 114, 255, 0.34);
  background:
    radial-gradient(circle at 94% 8%, rgba(106, 114, 255, 0.12), transparent 34%),
    rgba(255, 255, 255, 0.82);
}

.lesson-link.is-reviewed small {
  background: rgba(106, 114, 255, 0.1);
  color: #5058d8;
}

.lesson-link.is-reviewed b {
  background: rgba(106, 114, 255, 0.12);
  color: #5058d8;
}

.lesson-link.is-complete {
  border-color: rgba(42, 166, 120, 0.26);
  background: rgba(232, 247, 239, 0.76);
}

.lesson-link.is-complete b {
  background: #d8eee7;
  color: #287b73;
}

.lesson-link.is-draft {
  border-color: rgba(170, 182, 198, 0.18);
  background: rgba(247, 249, 251, 0.76);
}

.lesson-link.is-draft small,
.lesson-link.is-draft b {
  background: rgba(240, 169, 79, 0.12);
  color: #9a5a12;
}

@media (max-width: 760px) {
  .course-shell { width: min(100% - 20px, 1540px); }
  .course-nav {
    top: 6px;
    width: 100%;
    grid-template-columns: 38px minmax(0, 1fr) 38px;
  }
  .course-nav .nav-button {
    width: 38px;
    min-height: 40px;
  }
  .course-hero h1 { font-size: 34px; }
  .course-prompt { position: static; }
  .course-stage { min-height: 300px; padding: 14px; }
  .catalog-list { grid-template-columns: 1fr; }
  .percent-board { grid-template-columns: repeat(10, 18px); }
  .percent-cell { width: 18px; height: 18px; }
  .machine-flow { gap: 10px; font-size: 20px; }
  .machine-flow .quantity-bar { width: min(170px, 58vw) !important; }
  .expression-lab { grid-template-columns: 1fr; }
  .expression-scene { grid-template-columns: 1fr; }
  .direct-drag-hint {
    right: 16px;
    top: 16px;
  }
  .expression-reading { grid-template-columns: 1fr; }
  .expression-word-card { grid-template-columns: 1fr; }
  .expression-palette { grid-template-columns: auto 1fr auto; align-items: center; }
  .palette-tiles { grid-template-columns: repeat(4, minmax(54px, 1fr)); }
  .expression-tile.is-variable,
  .expression-tile.is-unit { width: 100%; }
  .expression-dropzone { min-height: 210px; padding: 14px; }
  .equation-responsive-board {
    width: 100%;
  }
  .desktop-equation-balance {
    display: none;
  }
  .mobile-equation-balance {
    display: grid;
    width: 100%;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: stretch;
    gap: 10px;
  }
  .balance-step-panel {
    width: 100%;
    margin: 0 auto 12px;
    border-radius: 8px;
    flex-direction: column;
    align-items: stretch;
  }
  .balance-step-panel button {
    width: 100%;
  }
  .balance-step-panel span {
    text-align: center;
  }
  .mobile-equation-title {
    display: block;
    grid-column: 1 / -1;
    color: #17384a;
    font-size: 22px;
    line-height: 1.1;
    text-align: center;
  }
  .mobile-balance-beam {
    grid-column: 1 / -1;
    height: 10px;
    border: 2px solid #17384a;
    border-radius: 999px;
    background: linear-gradient(180deg, #fff, #dfe8ef);
    box-shadow: 0 10px 20px rgba(23, 56, 74, 0.12);
  }
  .mobile-pan {
    display: grid;
    min-width: 0;
    align-content: start;
    gap: 7px;
    border: 2px solid rgba(23, 56, 74, 0.78);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.82);
    padding: 10px;
  }
  .mobile-pan > span,
  .mobile-pan > em {
    color: #55706f;
    font-size: 13px;
    font-style: normal;
    font-weight: 820;
    text-align: center;
  }
  .mobile-drag-zone {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 6px;
    min-height: 58px;
    border: 2px dashed rgba(45, 115, 214, 0.32);
    border-radius: 8px;
    background: rgba(247, 251, 255, 0.9);
    color: #17384a;
    cursor: grab;
    touch-action: none;
  }
  .mobile-drag-zone:active,
  .mobile-drag-zone.is-dragging-source {
    cursor: grabbing;
    border-color: rgba(45, 115, 214, 0.68);
    background: #eef6ff;
  }
  .mini-x,
  .mini-one,
  .mini-neg,
  .mini-zero {
    display: grid;
    min-width: 32px;
    min-height: 30px;
    place-items: center;
    border: 2px solid #2d73d6;
    border-radius: 8px;
    background: linear-gradient(145deg, #fff, #dfeaff);
    font-size: 16px;
    font-weight: 900;
  }
  .mini-one {
    border-color: #3c9b8f;
    background: linear-gradient(145deg, #fff, #d8eee7);
  }
  .mini-neg {
    border-color: #d36b62;
    background: linear-gradient(145deg, #fff, #ffe2de);
    color: #8f3e38;
  }
  .result-zone {
    min-height: 68px;
    border-style: solid;
    border-color: #f0a94f;
    background: #ffe9bd;
    font-size: 28px;
    font-weight: 900;
  }
  .mobile-equation-balance p {
    grid-column: 1 / -1;
    color: #17384a;
    font-size: 15px;
    font-weight: 840;
    text-align: center;
  }
}

@media (max-width: 360px) {
  .mobile-equation-balance {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 460px) {
  .expression-palette { grid-template-columns: 1fr; }
  .direct-drag-hint {
    position: static;
    justify-self: start;
    margin-top: -2px;
  }
  .palette-tiles { grid-template-columns: repeat(4, minmax(46px, 1fr)); }
  .palette-note { display: none; }
  .expression-head strong { font-size: 24px; }
}

@media (prefers-reduced-motion: reduce) {
  .expression-dropzone,
  .expression-palette { transition: none; }
}

/* Lesson studio shell: align course pages with the dashboard-style product frame. */
.lesson-studio-shell {
  width: min(1680px, calc(100% - 18px));
  padding-top: 6px;
}

.lesson-studio-shell .course-nav {
  position: static;
  grid-template-columns: 40px minmax(0, 220px) 40px;
  margin-bottom: 6px;
}

.lesson-studio-shell .course-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  min-height: 62px;
  margin-bottom: 8px;
  border-color: rgba(48, 75, 116, 0.13);
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 16px 46px rgba(35, 63, 102, 0.08);
  backdrop-filter: blur(24px) saturate(160%);
}

.lesson-studio-shell .course-hero h1 {
  font-size: 30px;
  line-height: 1.12;
}

.lesson-dashboard-strip {
  display: none;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 10px;
}

.lesson-dashboard-strip article {
  display: grid;
  gap: 5px;
  min-height: 76px;
  border: 1px solid rgba(48, 75, 116, 0.13);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 14px 38px rgba(35, 63, 102, 0.08);
  padding: 12px 14px;
}

.lesson-dashboard-strip span {
  color: #607080;
  font-size: 12px;
  font-weight: 820;
}

.lesson-dashboard-strip strong {
  overflow-wrap: anywhere;
  color: #17384a;
  font-size: 16px;
  line-height: 1.28;
  font-weight: 880;
}

.lesson-dashboard-strip .principle-card {
  background: linear-gradient(135deg, #edf6ff 0%, #e5f7f4 100%);
}

.lesson-journey {
  display: none;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 8px;
  margin: 0 0 10px;
  border: 1px solid rgba(48, 75, 116, 0.13);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.74);
  box-shadow: 0 14px 38px rgba(35, 63, 102, 0.07);
  padding: 8px;
}

.lesson-proofbar {
  display: none;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin: 0 0 10px;
  border: 1px solid rgba(48, 75, 116, 0.13);
  border-radius: 8px;
  background:
    radial-gradient(circle at 6% 0%, rgba(255, 255, 255, 0.94), transparent 34%),
    linear-gradient(135deg, rgba(247, 251, 255, 0.84), rgba(235, 249, 242, 0.72));
  box-shadow: 0 14px 38px rgba(35, 63, 102, 0.07);
  padding: 8px;
}

.lesson-proofbar article {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr) auto;
  align-items: center;
  gap: 8px;
  min-height: 46px;
  border: 1px solid rgba(31, 111, 229, 0.1);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  padding: 8px 10px;
}

.lesson-proofbar span {
  display: grid;
  width: 26px;
  height: 26px;
  place-items: center;
  border-radius: 50%;
  background: rgba(31, 111, 229, 0.1);
  color: #1f6fe5;
  font-size: 12px;
  font-weight: 900;
}

.lesson-proofbar strong {
  overflow: hidden;
  color: #17384a;
  font-size: 13px;
  font-weight: 900;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-proofbar small {
  justify-self: end;
  border-radius: 999px;
  background: rgba(170, 182, 198, 0.12);
  padding: 4px 8px;
  color: #607080;
  font-size: 11px;
  font-weight: 850;
  white-space: nowrap;
}

.lesson-proofbar article.is-done {
  border-color: rgba(42, 166, 120, 0.24);
  background: rgba(235, 249, 242, 0.86);
}

.lesson-proofbar article.is-done span {
  background: #2aa678;
  color: #ffffff;
}

.lesson-proofbar article.is-done small {
  background: rgba(42, 166, 120, 0.12);
  color: #287b73;
}

.lesson-proofbar article.is-locked {
  border-color: rgba(240, 169, 79, 0.18);
  background: rgba(255, 249, 236, 0.78);
}

.lesson-proofbar article.is-locked span,
.lesson-proofbar article.is-locked small {
  background: rgba(240, 169, 79, 0.12);
  color: #9a5a12;
}

.lesson-action-board {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  margin: 0 0 6px;
}

.lesson-action-board article {
  display: grid;
  align-content: start;
  gap: 6px;
  min-height: 0;
  border: 1px solid rgba(48, 75, 116, 0.13);
  border-radius: 8px;
  background:
    radial-gradient(circle at 10% 0%, rgba(255, 255, 255, 0.96), transparent 38%),
    linear-gradient(145deg, rgba(255, 255, 255, 0.84), rgba(245, 251, 249, 0.78));
  box-shadow: 0 14px 38px rgba(35, 63, 102, 0.08);
  padding: 8px 10px;
}

.lesson-action-board article:not(.lesson-action-primary) {
  display: none;
}

.lesson-action-board span {
  color: #607080;
  font-size: 12px;
  font-weight: 860;
}

.lesson-action-board strong {
  overflow-wrap: anywhere;
  color: #17384a;
  font-size: 16px;
  line-height: 1.26;
  font-weight: 920;
}

.lesson-action-board p {
  display: none;
  margin: 0;
  color: #3c5b67;
  font-size: 13px;
  font-weight: 740;
  line-height: 1.45;
}

.lesson-action-primary {
  position: relative;
  grid-template-columns: minmax(0, 1fr) auto;
  background:
    radial-gradient(circle at 8% 0%, rgba(255, 255, 255, 0.98), transparent 40%),
    linear-gradient(135deg, #edf6ff 0%, #e7f8f2 100%) !important;
}

.lesson-action-primary span,
.lesson-action-primary strong,
.lesson-action-primary p {
  grid-column: 1;
}

.lesson-action-primary a {
  grid-column: 2;
  grid-row: 1 / span 3;
  align-self: center;
  display: inline-grid;
  min-width: 84px;
  min-height: 34px;
  place-items: center;
  border-radius: 999px;
  background: #1f6fe5;
  color: #ffffff;
  font-size: 13px;
  font-weight: 900;
  text-decoration: none;
  box-shadow: 0 14px 28px rgba(31, 111, 229, 0.2);
}

.lesson-action-primary a:hover,
.lesson-action-primary a:focus-visible {
  background: #155bc5;
  outline: none;
  transform: translateY(-1px);
}

.journey-step {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  grid-template-rows: auto auto;
  column-gap: 7px;
  row-gap: 2px;
  align-items: center;
  min-height: 58px;
  border: 1px solid rgba(31, 111, 229, 0.1);
  border-radius: 8px;
  background: rgba(247, 251, 255, 0.78);
  padding: 9px 10px;
  color: #4c5e77;
  text-decoration: none;
  transition: background-color 160ms ease, border-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

.journey-step b {
  grid-row: 1 / span 2;
  display: grid;
  width: 24px;
  height: 24px;
  place-items: center;
  border-radius: 50%;
  background: rgba(31, 111, 229, 0.1);
  color: #1f6fe5;
  font-size: 12px;
  font-weight: 900;
}

.journey-step span {
  overflow: hidden;
  color: #17384a;
  font-size: 13px;
  font-weight: 900;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.journey-step small {
  overflow: hidden;
  color: #6c7b90;
  font-size: 11px;
  font-weight: 720;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.journey-step:hover,
.journey-step.is-active {
  transform: translateY(-1px);
  border-color: rgba(31, 111, 229, 0.32);
  background: #edf6ff;
  box-shadow: 0 12px 28px rgba(31, 111, 229, 0.12);
}

.journey-step.is-active b {
  background: #1f6fe5;
  color: #fff;
}

.journey-step.is-done {
  border-color: rgba(42, 166, 120, 0.24);
  background: rgba(235, 249, 242, 0.86);
}

.journey-step.is-done b {
  background: #2aa678;
  color: #fff;
}

.journey-step.is-done b::before {
  content: "✓";
}

.journey-step.is-done b {
  font-size: 0;
}

.journey-step.is-done b::before {
  font-size: 12px;
}

.lesson-studio {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr) 300px;
  grid-template-areas:
    "steps main panel"
    "steps practice panel"
    "steps mistake panel";
  gap: 12px;
  align-items: start;
}

.lesson-stepper {
  grid-area: steps;
  position: sticky;
  top: 74px;
  display: grid;
  gap: 7px;
  border: 1px solid rgba(48, 75, 116, 0.13);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.76);
  box-shadow: 0 18px 48px rgba(35, 63, 102, 0.08);
  backdrop-filter: blur(24px) saturate(160%);
  padding: 10px;
}

.lesson-stepper a {
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr);
  grid-template-rows: auto auto auto;
  gap: 2px 7px;
  align-items: center;
  min-height: 56px;
  border-radius: 8px;
  color: #4c5e77;
  text-decoration: none;
  font-size: 13px;
  font-weight: 780;
  padding: 7px 7px 7px 6px;
}

.lesson-stepper b {
  grid-row: 1 / span 3;
  display: grid;
  width: 22px;
  height: 22px;
  place-items: center;
  border-radius: 50%;
  background: rgba(31, 111, 229, 0.1);
  color: #1f6fe5;
  font-size: 12px;
}

.lesson-stepper span,
.lesson-stepper small,
.lesson-stepper em {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-stepper span {
  color: #17384a;
  font-weight: 900;
}

.lesson-stepper small {
  color: #6c7b90;
  font-size: 10px;
  font-weight: 720;
}

.lesson-stepper em {
  width: max-content;
  border-radius: 999px;
  background: rgba(170, 182, 198, 0.12);
  padding: 3px 7px;
  color: #7c899a;
  font-size: 10px;
  font-style: normal;
  font-weight: 900;
}

.lesson-stepper a:hover,
.lesson-stepper a.is-active {
  background: #e9f2ff;
  color: #155bc5;
}

.lesson-stepper a[aria-current="step"] b {
  background: #1f6fe5;
  color: #fff;
  box-shadow: 0 8px 18px rgba(31, 111, 229, 0.22);
}

.lesson-stepper a.is-done {
  background: rgba(235, 249, 242, 0.76);
}

.lesson-stepper a.is-done b {
  background: #2aa678;
  color: #fff;
  font-size: 0;
}

.lesson-stepper a.is-done b::before {
  content: "✓";
  font-size: 12px;
}

.lesson-stepper a.is-done em {
  background: rgba(42, 166, 120, 0.12);
  color: #287b73;
}

.lesson-stepper a.is-active em {
  background: rgba(31, 111, 229, 0.12);
  color: #155bc5;
}

.lesson-main {
  grid-area: main;
  display: grid;
  gap: 12px;
  min-width: 0;
}

.lesson-practice {
  grid-area: practice;
}

.lesson-mistake-panel {
  grid-area: mistake;
  display: grid;
  gap: 10px;
}

.lesson-studio .course-prompt,
.lesson-studio .model-card {
  grid-area: auto;
}

.lesson-studio .model-card {
  order: -1;
}

.lesson-studio .course-prompt {
  position: relative;
  top: auto;
  min-height: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(210px, 300px);
  align-items: center;
  border-color: rgba(31, 111, 229, 0.12);
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 18px 48px rgba(35, 63, 102, 0.08);
  padding: 18px;
}

.lesson-studio .course-prompt .eyebrow,
.lesson-studio .course-prompt h2,
.lesson-studio .course-prompt .feedback {
  grid-column: 1;
}

.lesson-studio .course-prompt h2 {
  margin: 6px 0 0;
  font-size: 26px;
}

.lesson-studio .choice-row {
  grid-column: 2;
  grid-row: 1 / span 3;
  min-width: 0;
}

.lesson-studio .model-card {
  display: grid;
  border-color: rgba(48, 75, 116, 0.13);
  background:
    radial-gradient(circle at 12% 0%, rgba(255, 255, 255, 0.98), transparent 34%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.84), rgba(242, 249, 248, 0.78));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.9),
    0 26px 80px rgba(35, 63, 102, 0.14);
}

.lesson-studio .model-head {
  order: 1;
}

.lesson-studio .visual-stage {
  order: 2;
}

.lesson-studio .formula-strip {
  order: 3;
  display: flex;
  min-width: 0;
  min-height: 42px;
  align-items: center;
  gap: 6px;
  margin-top: 10px;
  border-color: rgba(31, 111, 229, 0.1);
  background: rgba(255, 255, 255, 0.62);
  overflow: hidden;
}

.lesson-studio .formula-pill {
  display: inline-flex;
  max-width: min(220px, 38%);
  min-height: 24px;
  align-items: center;
  border-radius: 999px;
  background: rgba(31, 111, 229, 0.1);
  padding: 3px 9px;
  color: #155bc5;
  font-size: 12px;
  font-weight: 900;
  line-height: 1.1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-studio .formula-pill.green {
  background: rgba(42, 166, 120, 0.12);
  color: #287b73;
}

.lesson-studio .model-feedback {
  order: 4;
}

.lesson-studio .course-controls {
  order: 5;
}

.lesson-studio .model-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px;
  align-items: center;
  margin: 8px 8px 0;
  border: 1px solid rgba(31, 111, 229, 0.1);
  border-radius: 8px;
  background:
    radial-gradient(circle at 0% 0%, rgba(255, 255, 255, 0.98), transparent 42%),
    linear-gradient(135deg, rgba(237, 246, 255, 0.88) 0%, rgba(229, 247, 244, 0.78) 100%);
  padding: 8px 10px;
}

.lesson-studio .model-head > div {
  min-width: 0;
}

.lesson-studio .model-head .eyebrow {
  margin: 0 0 3px;
  font-size: 12px;
}

.lesson-studio .model-head h2 {
  margin: 0;
  color: #17384a;
  font-size: clamp(20px, 1.75vw, 28px);
  line-height: 1.12;
  letter-spacing: 0;
}

.lesson-studio .model-head .ghost-button {
  min-height: 38px;
  padding: 0 14px;
  border-radius: 8px;
}

.lesson-studio .visual-stage {
  position: relative;
  min-height: 560px;
  margin: 8px 8px 0;
  border-color: rgba(38, 112, 109, 0.16);
  border-radius: 8px;
  background:
    radial-gradient(circle at 18% 10%, rgba(255, 255, 255, 0.98), transparent 28%),
    radial-gradient(circle at 88% 16%, rgba(215, 239, 235, 0.54), transparent 30%),
    linear-gradient(rgba(31, 111, 229, 0.032) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 111, 229, 0.032) 1px, transparent 1px),
    linear-gradient(180deg, #fffdfa 0%, #f7fbff 54%, #edf7f5 100%);
  background-size: 26px 26px, 26px 26px, auto;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.96),
    inset 0 -28px 70px rgba(42, 166, 120, 0.08),
    0 18px 48px rgba(35, 63, 102, 0.08);
}

.lesson-studio .visual-stage::before {
  content: attr(data-stage-label);
  position: absolute;
  top: 12px;
  left: 12px;
  z-index: 1;
  border: 1px solid rgba(42, 166, 120, 0.16);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.78);
  padding: 5px 9px;
  color: #287b73;
  font-size: 11px;
  font-weight: 900;
  pointer-events: none;
}

.lesson-studio .model-feedback {
  margin-top: 8px;
  background: rgba(247, 253, 251, 0.68);
}

.lesson-studio .course-controls {
  margin-top: 10px;
}

.lesson-studio .practice-panel {
  margin: 0;
  background: linear-gradient(180deg, rgba(247, 255, 251, 0.94), rgba(234, 248, 241, 0.86));
}

.lesson-inspector {
  grid-area: panel;
  position: sticky;
  top: 74px;
  max-height: calc(100vh - 88px);
  overflow: auto;
  gap: 8px;
  padding-right: 2px;
  scrollbar-width: thin;
}

.lesson-inspector .mini-card {
  border-color: rgba(48, 75, 116, 0.12);
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 14px 38px rgba(35, 63, 102, 0.08);
  padding: 12px;
}

.lesson-inspector .mini-card .eyebrow {
  margin-bottom: 6px;
  font-size: 11px;
}

.lesson-inspector .mini-card h3,
.lesson-inspector .mini-card p {
  margin: 0;
}

.lesson-inspector .mini-card h3 {
  color: #17384a;
  font-size: 18px;
  line-height: 1.18;
}

.lesson-inspector .mini-card p,
.lesson-inspector .mini-card li {
  font-size: 13px;
  line-height: 1.42;
}

.lesson-inspector .mini-card ol {
  display: grid;
  gap: 7px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.lesson-inspector .mini-card li {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  align-items: start;
  gap: 8px;
}

.lesson-inspector .mini-card ol > li > b {
  display: grid;
  width: 24px;
  height: 24px;
  place-items: center;
  border-radius: 7px;
  background: rgba(31, 111, 229, 0.1);
  color: #1f6fe5;
  font-size: 11px;
  font-weight: 900;
}

.lesson-inspector .mini-card ol > li > span {
  min-width: 0;
}

.lesson-inspector .problem-card {
  background: linear-gradient(180deg, rgba(247, 255, 251, 0.96), rgba(232, 247, 239, 0.86));
}

.lesson-inspector .mistake-card {
  background: linear-gradient(180deg, rgba(255, 246, 247, 0.96), rgba(255, 235, 237, 0.86));
}

.neighbor-list {
  display: grid;
  gap: 7px;
  min-width: 0;
}

.neighbor-link {
  display: grid;
  gap: 3px;
  min-width: 0;
  min-height: 0;
  height: auto;
  border: 1px solid rgba(31, 111, 229, 0.14);
  border-radius: 8px;
  background: rgba(247, 251, 255, 0.82);
  padding: 8px;
  color: #17384a;
  text-decoration: none;
  transition: transform 140ms ease, border-color 140ms ease, background 140ms ease, box-shadow 140ms ease;
}

.neighbor-link:hover,
.neighbor-link:focus-visible {
  transform: translateY(-1px);
  border-color: rgba(31, 111, 229, 0.34);
  background: #edf6ff;
  box-shadow: 0 12px 26px rgba(35, 63, 102, 0.1);
  outline: none;
}

.neighbor-link em {
  color: #1f6fe5;
  font-size: 12px;
  font-style: normal;
  font-weight: 850;
}

.neighbor-link strong {
  overflow: visible;
  min-width: 0;
  overflow-wrap: anywhere;
  font-size: 14px;
  line-height: 1.18;
  font-weight: 880;
  text-overflow: clip;
  white-space: normal;
}

.neighbor-link small {
  color: #607080;
  font-size: 11px;
  font-weight: 720;
}

.neighbor-link b {
  display: block;
  width: auto !important;
  height: auto !important;
  min-width: 0;
  min-height: 0;
  overflow-wrap: anywhere;
  color: #4d6477;
  font-size: 10px;
  font-weight: 760;
  line-height: 1.32;
}

.neighbor-link.is-same-model {
  border-color: rgba(40, 123, 115, 0.22);
  background: linear-gradient(180deg, rgba(247, 253, 251, 0.94), rgba(232, 247, 239, 0.78));
}

.neighbor-link.is-same-model em {
  color: #287b73;
}

.neighbor-link.is-empty {
  border-style: dashed;
  background: rgba(247, 249, 251, 0.72);
  color: #7a8795;
}

@media (min-width: 1181px) {
  .lesson-studio-shell {
    width: min(1680px, calc(100% - 16px));
    padding-top: 5px;
    padding-bottom: 8px;
  }

  .lesson-studio-shell .course-nav {
    grid-template-columns: 38px minmax(0, 210px) 38px;
    gap: 7px;
    margin-bottom: 5px;
  }

  .lesson-studio-shell .course-nav .nav-button {
    width: 38px;
    min-height: 38px;
  }

  .lesson-studio-shell .course-nav .catalog-button {
    min-height: 38px;
    padding: 6px 12px;
  }

  .lesson-studio-shell .course-hero {
    min-height: 52px;
    margin-bottom: 6px;
    padding: 10px 14px;
  }

  .lesson-studio-shell .course-hero h1 {
    font-size: 24px;
    line-height: 1.08;
  }

  .lesson-studio-shell .course-hero .eyebrow {
    margin-bottom: 3px;
    font-size: 11px;
  }

  .lesson-studio-shell .top-focus {
    gap: 6px;
  }

  .lesson-studio-shell .top-focus span {
    min-height: 28px;
    padding: 5px 9px;
    font-size: 11px;
  }

  .lesson-action-board {
    margin-bottom: 6px;
  }

  .lesson-action-board article {
    padding: 7px 10px;
  }

  .lesson-action-board strong {
    font-size: 14px;
  }

  .lesson-action-primary a {
    min-width: 76px;
    min-height: 30px;
    font-size: 12px;
  }

  .lesson-studio {
    grid-template-columns: 132px minmax(0, 1fr) 286px;
    grid-template-rows: minmax(0, 1fr) 156px;
    grid-template-areas:
      "steps main panel"
      "steps practice mistake";
    gap: 8px;
    height: calc(100vh - 200px);
    min-height: 500px;
    max-height: 520px;
    overflow: hidden;
  }

  .lesson-stepper {
    top: 62px;
    gap: 5px;
    max-height: 100%;
    overflow: auto;
    padding: 7px;
  }

  .lesson-stepper a {
    grid-template-columns: 22px minmax(0, 1fr);
    min-height: 42px;
    gap: 1px 6px;
    padding: 5px 6px;
    font-size: 12px;
  }

  .lesson-stepper b {
    width: 20px;
    height: 20px;
    font-size: 11px;
  }

  .lesson-stepper small,
  .lesson-stepper em {
    display: none;
  }

  .lesson-main {
    gap: 8px;
    max-height: 100%;
    overflow: auto;
  }

  .lesson-studio .course-prompt {
    grid-template-columns: minmax(0, 1fr) minmax(180px, 240px);
    padding: 10px 12px;
  }

  .lesson-studio .course-prompt h2 {
    margin-top: 3px;
    font-size: 17px;
    line-height: 1.2;
  }

  .lesson-studio .course-prompt .feedback {
    display: none;
  }

  .lesson-studio .model-card {
    max-height: 100%;
    overflow: hidden;
  }

  .lesson-studio .model-head {
    gap: 8px;
    margin: 6px 6px 0;
    padding: 6px 8px;
  }

  .lesson-studio .model-head .eyebrow {
    display: none;
  }

  .lesson-studio .model-head h2 {
    font-size: 17px;
    line-height: 1.14;
  }

  .lesson-studio .model-head .ghost-button {
    min-height: 30px;
    padding: 0 10px;
    font-size: 12px;
  }

  .lesson-studio .visual-stage,
  .course-stage.is-direct-stage {
    min-height: 0;
    height: 300px !important;
    max-height: 300px;
    margin: 6px;
    padding: 10px;
    overflow: hidden;
  }

  .lesson-studio .visual-stage::before {
    top: 8px;
    left: 8px;
    padding: 4px 8px;
    font-size: 10px;
  }

  .course-stage svg {
    width: min(100%, 680px);
    max-height: 278px;
  }

  .manipulative,
  .equation-responsive-board,
  .expression-lab {
    min-height: 0;
    max-height: 278px;
  }

  .desktop-equation-balance,
  .expression-lab svg,
  .equation-responsive-board svg {
    max-height: 278px;
  }

  .lesson-studio .formula-strip {
    min-height: 34px;
    margin: 6px 6px 0;
    padding: 6px 8px;
  }

  .lesson-studio .model-feedback {
    display: none;
  }

  .lesson-studio .course-controls {
    display: none;
  }

  .lesson-inspector {
    top: 62px;
    max-height: 100%;
    gap: 7px;
  }

  .lesson-inspector .mini-card {
    padding: 9px 10px;
  }

  .lesson-inspector .mini-card .eyebrow {
    margin-bottom: 4px;
    font-size: 10px;
  }

  .lesson-inspector .mini-card h3 {
    font-size: 15px;
  }

  .lesson-inspector .mini-card p,
  .lesson-inspector .mini-card li {
    font-size: 12px;
    line-height: 1.34;
  }

  .lesson-inspector .mini-card ol {
    gap: 5px;
  }

  .lesson-inspector .mini-card li {
    grid-template-columns: 22px minmax(0, 1fr);
    gap: 6px;
  }

  .lesson-inspector .mini-card ol > li > b {
    width: 20px;
    height: 20px;
    font-size: 10px;
  }

  .neighbor-link {
    padding: 6px 7px;
  }

  .neighbor-link small,
  .neighbor-link b {
    display: none;
  }

  .lesson-practice {
    max-height: 156px;
    overflow: auto;
    padding: 10px;
  }

  .lesson-practice h2 {
    font-size: 15px;
    line-height: 1.16;
  }

  .practice-list {
    gap: 8px;
  }

  .practice-card {
    gap: 7px;
  }

  .practice-card-head,
  .practice-question span,
  .practice-question small,
  .practice-diagnosis {
    display: none;
  }

  .practice-question strong {
    font-size: 13px;
  }

  .practice-card .answer-options {
    gap: 6px;
    margin-top: 6px;
  }

  .answer-options button {
    min-height: 30px;
    padding: 5px 7px;
    font-size: 12px;
  }

  .lesson-mistake-panel {
    max-height: 156px;
    overflow: auto;
    gap: 8px;
  }

  .lesson-mistake-panel .mini-card {
    padding: 10px;
  }

  .lesson-mistake-panel .mini-card p {
    font-size: 12px;
    line-height: 1.34;
  }

  .complete-button {
    min-height: 38px;
    font-size: 13px;
  }

  .completion-evidence {
    display: none;
  }
}

/* Reference cockpit polish: blue-white dashboard panels inspired by the project reference. */
.lesson-studio-shell .course-hero,
.lesson-dashboard-strip article,
.lesson-proofbar article,
.lesson-action-board article,
.lesson-stepper,
.lesson-studio .course-prompt,
.lesson-studio .model-card,
.lesson-inspector .mini-card,
.lesson-practice,
.lesson-mistake-panel .mini-card,
.catalog-dialog {
  border-color: rgba(64, 111, 178, 0.14);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(248, 252, 255, 0.86));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.92),
    0 12px 34px rgba(38, 77, 130, 0.07);
}

.lesson-dashboard-strip article span,
.lesson-proofbar article strong,
.lesson-action-board span,
.lesson-inspector .mini-card .eyebrow,
.lesson-studio .model-head .eyebrow,
.lesson-studio .course-prompt .eyebrow,
.lesson-practice .eyebrow,
.lesson-mistake-panel .eyebrow {
  color: #2f65ad;
}

.lesson-studio .model-head {
  border-color: rgba(64, 111, 178, 0.13);
  background:
    linear-gradient(135deg, rgba(239, 247, 255, 0.96), rgba(250, 253, 255, 0.92));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9);
}

.lesson-studio .visual-stage {
  border-color: rgba(69, 128, 202, 0.16);
  background:
    linear-gradient(rgba(31, 111, 229, 0.042) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 111, 229, 0.042) 1px, transparent 1px),
    radial-gradient(circle at 16% 8%, rgba(255, 255, 255, 0.96), transparent 31%),
    radial-gradient(circle at 86% 12%, rgba(214, 232, 255, 0.52), transparent 34%),
    linear-gradient(180deg, #ffffff 0%, #f7fbff 56%, #eff7ff 100%);
  background-size: 26px 26px, 26px 26px, auto, auto, auto;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.96),
    inset 0 -24px 58px rgba(31, 111, 229, 0.055),
    0 12px 30px rgba(38, 77, 130, 0.06);
}

.lesson-studio .visual-stage::before {
  border-color: rgba(31, 111, 229, 0.16);
  background: rgba(255, 255, 255, 0.82);
  color: #1f6fe5;
}

.lesson-stepper a:hover,
.lesson-stepper a.is-active,
.lesson-stepper a[aria-current="step"] {
  background: #eaf3ff;
  color: #155bc5;
}

.lesson-stepper a[aria-current="step"] b,
.lesson-stepper a.is-active b,
.complete-button {
  background: linear-gradient(145deg, #2f87ff, #155bc5);
  color: #fff;
}

.lesson-action-primary a,
.catalog-button:hover,
.nav-button:hover {
  border-color: rgba(31, 111, 229, 0.18);
  background: #eaf3ff;
  color: #155bc5;
}

.formula-strip,
.model-feedback,
.course-control,
.practice-card,
.answer-options button,
.neighbor-link {
  border-color: rgba(64, 111, 178, 0.13);
  background: rgba(255, 255, 255, 0.8);
}

.lesson-studio .lesson-panel .mini-card,
.lesson-studio .lesson-panel .mini-card:nth-child(1),
.lesson-studio .lesson-panel .mini-card:nth-child(2),
.lesson-studio .lesson-panel .mini-card:nth-child(3) {
  border-color: rgba(64, 111, 178, 0.14);
}

.lesson-studio .lesson-inspector .problem-card {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(239, 247, 255, 0.86));
}

@media (min-width: 1181px) and (max-height: 760px) {
  .lesson-studio-shell {
    min-height: 100vh;
    overflow-x: hidden;
    overflow-y: auto;
  }

  .lesson-dashboard-strip {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 6px;
    margin-bottom: 6px;
  }

  .lesson-dashboard-strip article {
    min-height: 42px;
    padding: 7px 9px;
  }

  .lesson-dashboard-strip span {
    font-size: 10px;
  }

  .lesson-dashboard-strip strong {
    font-size: 12px;
    line-height: 1.16;
  }

  .lesson-proofbar {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
    margin-bottom: 6px;
  }

  .lesson-proofbar article {
    min-height: 38px;
    grid-template-columns: 22px minmax(0, 1fr);
    gap: 6px;
    padding: 6px 8px;
  }

  .lesson-proofbar span {
    width: 22px;
    height: 22px;
    font-size: 11px;
  }

  .lesson-proofbar strong {
    font-size: 12px;
  }

  .lesson-proofbar small {
    display: none;
  }

  .lesson-studio {
    grid-template-rows: auto auto;
    height: auto;
    min-height: 0;
    max-height: none;
    overflow: visible;
  }

  .lesson-stepper,
  .lesson-inspector {
    position: static;
    max-height: none;
  }

  .lesson-main,
  .lesson-studio .model-card {
    max-height: none;
    overflow: visible;
  }

  .lesson-studio .visual-stage,
  .course-stage.is-direct-stage {
    height: 300px !important;
    max-height: none;
  }

  .lesson-practice,
  .lesson-mistake-panel {
    max-height: 178px;
    overflow: auto;
  }

  .lesson-practice {
    align-self: start;
  }

  .lesson-mistake-panel {
    align-self: start;
  }
}

@media (max-width: 1180px) {
  .lesson-dashboard-strip {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .lesson-proofbar {
    grid-template-columns: 1fr;
  }

  .lesson-action-board {
    grid-template-columns: 1fr;
  }

  .lesson-journey {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    overflow: visible;
    scroll-snap-type: none;
    scrollbar-width: auto;
  }

  .lesson-journey::-webkit-scrollbar {
    display: none;
  }

  .journey-step {
    min-width: 0;
    scroll-snap-align: start;
  }

  .journey-step small {
    overflow: visible;
    overflow-wrap: anywhere;
    text-overflow: clip;
    white-space: normal;
  }

  .lesson-studio {
    grid-template-columns: 1fr;
    grid-template-areas:
      "steps"
      "main"
      "panel"
      "practice"
      "mistake";
  }

  .lesson-stepper {
    position: static;
    display: flex;
    max-width: 100%;
    overflow-x: auto;
    overflow-y: hidden;
    overscroll-behavior-x: contain;
    scroll-snap-type: x proximity;
    scrollbar-width: none;
    -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 18px, #000 calc(100% - 18px), transparent 100%);
    mask-image: linear-gradient(90deg, transparent 0, #000 18px, #000 calc(100% - 18px), transparent 100%);
  }

  .lesson-stepper::-webkit-scrollbar {
    display: none;
  }

  .lesson-stepper a {
    flex: 0 0 auto;
    width: min(112px, 31vw);
    min-width: 0;
    min-height: 58px;
    padding: 7px 8px;
    scroll-snap-align: start;
  }

  .lesson-stepper small {
    overflow: visible;
    overflow-wrap: anywhere;
    text-overflow: clip;
    white-space: normal;
  }

  .lesson-inspector {
    position: static;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  .lesson-studio-shell {
    width: calc(100% - 16px);
    max-width: calc(100vw - 16px);
    min-width: 0;
  }

  .lesson-studio-shell,
  .lesson-studio,
  .lesson-main,
  .lesson-inspector,
  .lesson-studio .course-prompt,
  .lesson-studio .model-card,
  .lesson-practice,
  .lesson-mistake-panel {
    min-width: 0;
    max-width: calc(100vw - 16px);
  }

  .lesson-dashboard-strip {
    grid-template-columns: 1fr;
  }

  .lesson-dashboard-strip,
  .lesson-journey,
  .lesson-proofbar {
    display: none;
  }

  .lesson-action-board {
    margin-bottom: 8px;
  }

  .lesson-action-board article:not(.lesson-action-primary) {
    display: none;
  }

  .lesson-action-board article {
    min-height: 0;
    padding: 10px 12px;
  }

  .lesson-action-board p {
    display: none;
  }

  .lesson-studio-shell .course-hero {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    min-height: 0;
    gap: 10px;
    margin-bottom: 8px;
    padding: 10px 12px;
  }

  .lesson-studio-shell .course-hero .eyebrow {
    display: none;
  }

  .lesson-studio-shell .course-hero h1 {
    font-size: 24px;
    line-height: 1.16;
    overflow-wrap: anywhere;
  }

  .lesson-studio-shell .top-focus {
    justify-content: end;
    gap: 6px;
  }

  .lesson-studio-shell .top-focus span {
    padding: 6px 9px;
    font-size: 11px;
  }

  .lesson-studio-shell .top-focus span:not(:first-child) {
    display: none;
  }

  .lesson-studio .course-prompt {
    grid-template-columns: 1fr;
  }

  .lesson-studio .course-prompt .eyebrow,
  .lesson-studio .course-prompt h2,
  .lesson-studio .course-prompt .feedback,
  .lesson-studio .choice-row {
    grid-column: auto;
    grid-row: auto;
  }

  .lesson-studio .course-prompt h2 {
    font-size: 22px;
  }

  .lesson-studio .visual-stage {
    min-height: 340px;
  }

  .lesson-studio .formula-strip {
    flex-wrap: wrap;
    max-height: none;
    overflow: visible;
    white-space: normal;
  }

  .lesson-studio .formula-pill {
    max-width: 100%;
    overflow: visible;
    text-overflow: clip;
    white-space: normal;
  }

  .lesson-inspector {
    grid-template-columns: 1fr;
  }

  .lesson-stepper {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    overflow: visible;
    -webkit-mask-image: none;
    mask-image: none;
  }

  .lesson-stepper a {
    width: auto;
    min-width: 0;
    min-height: 56px;
  }
}

@media (max-width: 460px) {
  .lesson-studio-shell .course-nav {
    grid-template-columns: 44px minmax(0, 1fr) 44px;
  }

  .lesson-studio-shell .course-nav .nav-button {
    width: 44px;
    min-height: 44px;
  }

  .lesson-stepper a {
    width: auto;
    min-width: 0;
    font-size: 12px;
  }

  .lesson-stepper small {
    display: none;
  }

  .lesson-stepper em {
    max-width: 100%;
    padding: 2px 6px;
    font-size: 9px;
  }
}

/* Course visual stage polish: fit direct manipulation models into the cockpit stage. */
.lesson-studio .visual-stage {
  background:
    linear-gradient(rgba(31, 111, 229, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 111, 229, 0.045) 1px, transparent 1px),
    radial-gradient(circle at 18% 8%, rgba(255, 255, 255, 0.96), transparent 30%),
    radial-gradient(circle at 82% 15%, rgba(214, 232, 255, 0.56), transparent 34%),
    linear-gradient(180deg, #ffffff 0%, #f6fbff 56%, #edf6ff 100%);
  background-size: 24px 24px, 24px 24px, auto, auto, auto;
}

.lesson-studio .formula-strip {
  background:
    radial-gradient(circle at 12% 0%, rgba(255, 255, 255, 0.96), transparent 38%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.9), rgba(239, 247, 255, 0.76));
}

.equation-responsive-board,
.expression-lab,
.manipulative {
  border-radius: 8px;
}

.desktop-equation-balance {
  filter: drop-shadow(0 14px 22px rgba(38, 77, 130, 0.12));
}

.balance-step-panel {
  border-color: rgba(64, 111, 178, 0.16);
  background:
    radial-gradient(circle at 12% 0%, rgba(255, 255, 255, 0.96), transparent 42%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(239, 247, 255, 0.84));
}

.expression-tile,
.touch-block,
.array-cell,
.fraction-part,
.percent-cell,
.quantity-bar {
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.92),
    inset 0 -8px 16px rgba(31, 111, 229, 0.06),
    0 8px 16px rgba(38, 77, 130, 0.1);
}

@media (min-width: 1181px) {
  .lesson-studio .visual-stage .expression-lab {
    height: 100%;
    min-height: 0;
    max-height: 278px;
    overflow: hidden;
  }

  .lesson-studio .visual-stage .expression-workbench {
    grid-template-rows: auto auto auto minmax(0, 1fr);
    gap: 5px;
    min-height: 0;
    height: 100%;
    padding: 8px;
    border-color: rgba(64, 111, 178, 0.14);
    background:
      radial-gradient(circle at 18% 8%, rgba(255, 255, 255, 0.96), transparent 32%),
      linear-gradient(145deg, rgba(255, 255, 255, 0.92), rgba(239, 247, 255, 0.86));
  }

  .lesson-studio .visual-stage .expression-head {
    min-height: 22px;
    font-size: 10px;
  }

  .lesson-studio .visual-stage .expression-head strong {
    font-size: 18px;
  }

  .lesson-studio .visual-stage .expression-word-card {
    grid-template-columns: auto auto auto minmax(0, 1fr);
    gap: 5px;
    padding: 5px 6px;
  }

  .lesson-studio .visual-stage .expression-word-card span,
  .lesson-studio .visual-stage .expression-word-card i,
  .lesson-studio .visual-stage .expression-word-card em,
  .lesson-studio .visual-stage .expression-action-chip {
    min-height: 24px;
    padding: 0 8px;
    font-size: 11px;
  }

  .lesson-studio .visual-stage .expression-word-card b,
  .lesson-studio .visual-stage .expression-task,
  .lesson-studio .visual-stage .expression-invariant {
    display: none;
  }

  .lesson-studio .visual-stage .expression-reading {
    gap: 5px;
  }

  .lesson-studio .visual-stage .expression-reading span {
    gap: 1px;
    padding: 5px 7px;
  }

  .lesson-studio .visual-stage .expression-reading b {
    font-size: 9px;
  }

  .lesson-studio .visual-stage .expression-reading em {
    font-size: 14px;
  }

  .lesson-studio .visual-stage .expression-scene {
    grid-template-columns: minmax(0, 1fr) 118px;
    gap: 6px;
    min-height: 0;
    height: 128px;
    max-height: 128px;
    align-items: stretch;
    overflow: hidden;
    padding: 7px;
  }

  .lesson-studio .visual-stage .expression-dropzone,
  .lesson-studio .visual-stage .expression-palette {
    min-height: 0;
    height: 100%;
    max-height: 114px;
    overflow: hidden;
  }

  .lesson-studio .visual-stage .expression-dropzone {
    gap: 6px;
    padding: 23px 8px 7px;
  }

  .lesson-studio .visual-stage .dropzone-label {
    top: 7px;
    left: 8px;
    font-size: 10px;
  }

  .lesson-studio .visual-stage .expression-palette {
    gap: 6px;
    padding: 7px;
  }

  .lesson-studio .visual-stage .palette-label,
  .lesson-studio .visual-stage .palette-note {
    display: none;
  }

  .lesson-studio .visual-stage .palette-tiles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 6px;
  }

  .lesson-studio .visual-stage .palette-note {
    display: none;
  }

  .lesson-studio .visual-stage .expression-palette .expression-tile {
    width: 100%;
    min-width: 0;
    height: 32px;
  }

  .lesson-studio .visual-stage .expression-tile {
    height: 36px;
    min-width: 40px;
    border-width: 1px;
    font-size: 15px;
  }

  .lesson-studio .visual-stage .expression-dropzone .expression-tile {
    min-width: 46px;
  }

  .lesson-studio .visual-stage .direct-drag-hint {
    display: none;
  }

  .lesson-studio .visual-stage .equation-responsive-board {
    display: grid;
    align-content: center;
    min-height: 0;
    height: 100%;
    max-height: 278px;
    overflow: hidden;
    border: 1px solid rgba(64, 111, 178, 0.12);
    background:
      radial-gradient(circle at 18% 8%, rgba(255, 255, 255, 0.96), transparent 34%),
      linear-gradient(180deg, rgba(255, 255, 255, 0.88), rgba(240, 247, 255, 0.78));
    padding: 4px 10px;
  }

  .lesson-studio .visual-stage .desktop-equation-balance {
    max-height: 214px;
  }

  .lesson-studio .visual-stage .balance-step-panel {
    width: min(100%, 620px);
    min-height: 38px;
    margin: -2px auto 0;
    padding: 5px 8px;
  }

  .lesson-studio .visual-stage .balance-step-panel button {
    min-height: 28px;
    padding: 0 12px;
    font-size: 11px;
  }

  .lesson-studio .visual-stage .balance-step-panel span {
    font-size: 10px;
  }
}

/* Reference course cockpit pass: bring the manipulative stage into the first viewport. */
@media (min-width: 1181px) {
  .lesson-studio-shell {
    width: min(1680px, calc(100% - 16px));
    padding-top: 4px;
  }

  .lesson-studio-shell .course-nav {
    grid-template-columns: 34px minmax(0, 190px) 34px;
    min-height: 34px;
    height: 34px;
    margin-bottom: 4px;
  }

  .lesson-studio-shell .course-nav .nav-button {
    width: 34px;
    min-height: 34px;
  }

  .lesson-studio-shell .catalog-button {
    min-height: 34px;
    padding: 3px 8px;
  }

  .lesson-studio-shell .catalog-button strong {
    display: none;
  }

  .lesson-studio-shell .course-hero {
    min-height: 46px;
    margin-bottom: 5px;
    padding: 8px 12px;
  }

  .lesson-studio-shell .course-hero h1 {
    font-size: 24px;
    line-height: 1.08;
  }

  .lesson-studio-shell .top-focus span {
    min-height: 24px;
    padding: 0 9px;
    font-size: 11px;
  }

  .lesson-dashboard-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    min-height: 38px;
    margin-bottom: 5px;
  }

  .lesson-dashboard-strip article {
    min-height: 38px;
    padding: 5px 8px;
  }

  .lesson-dashboard-strip span {
    font-size: 9px;
  }

  .lesson-dashboard-strip strong {
    font-size: 12px;
    line-height: 1.14;
  }

  .lesson-proofbar {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    min-height: 38px;
    margin-bottom: 5px;
  }

  .lesson-proofbar article {
    min-height: 38px;
    padding: 5px 8px;
  }

  .lesson-proofbar strong {
    font-size: 12px;
  }

  .lesson-proofbar small {
    font-size: 10px;
  }

  .lesson-action-board {
    display: none;
  }

  .lesson-studio {
    grid-template-columns: 132px minmax(0, 1fr) 286px;
    grid-template-rows: 500px 170px;
    gap: 8px;
  }

  .lesson-stepper {
    max-height: 500px;
    padding: 8px;
  }

  .lesson-stepper a {
    min-height: 42px;
  }

  .lesson-main {
    grid-template-rows: 358px 134px;
    gap: 8px;
    min-height: 0;
  }

  .lesson-studio .model-card {
    min-height: 0;
    max-height: 358px;
    overflow: hidden;
  }

  .lesson-studio .model-head {
    min-height: 38px;
  }

  .lesson-studio .model-head h2 {
    font-size: 16px;
    line-height: 1.12;
  }

  .lesson-studio .formula-strip {
    min-height: 38px;
    max-height: 38px;
    overflow: hidden;
  }

  .lesson-studio .model-feedback {
    display: none;
  }

  .lesson-studio .visual-stage {
    height: 272px;
    min-height: 272px;
  }

  .lesson-studio .course-prompt {
    max-height: 134px;
    overflow: hidden;
    padding: 12px;
  }

  .lesson-studio .course-prompt h2 {
    font-size: 18px;
    line-height: 1.12;
  }

  .lesson-studio .choice-row {
    align-content: center;
  }

  .lesson-inspector {
    max-height: 500px;
    overflow: hidden;
  }

  .lesson-inspector .mini-card {
    padding: 10px;
  }

  .lesson-inspector h3,
  .lesson-inspector p,
  .lesson-inspector li {
    font-size: 12px;
    line-height: 1.32;
  }

  .lesson-practice {
    max-height: 170px;
    overflow: hidden;
  }

  .lesson-mistake-panel {
    max-height: 124px;
    overflow: hidden;
  }
}

/* QA cockpit reading pass: avoid clipping lesson text while keeping the model first. */
@media (min-width: 1181px) {
  .course-system-shell {
    display: grid;
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 10px;
    width: min(1880px, calc(100% - 18px));
    min-height: 100vh;
    margin: 0 auto;
    padding: 8px;
  }

  .course-sidebar {
    position: sticky;
    top: 10px;
    display: grid;
    align-content: start;
    gap: 14px;
    height: calc(100vh - 20px);
    border: 1px solid rgba(70, 108, 158, 0.14);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.72);
    box-shadow:
      inset 0 1px 0 rgba(255, 255, 255, 0.94),
      0 14px 34px rgba(38, 77, 130, 0.08);
    backdrop-filter: blur(24px) saturate(160%);
    padding: 10px;
  }

  .course-system-shell .lesson-studio-shell {
    width: 100%;
    max-width: none;
    min-width: 0;
    padding-top: 0;
  }

  .lesson-studio {
    grid-template-columns: 128px minmax(0, 1fr) 276px;
    grid-template-rows: 504px 190px;
  }

  .lesson-main {
    grid-template-rows: 372px 120px;
  }

  .lesson-studio .model-card {
    display: grid;
    grid-template-rows: 38px 34px minmax(0, 1fr);
    max-height: 372px;
    overflow: visible;
  }

  .lesson-studio .model-head {
    order: 1;
    min-height: 38px;
    max-height: 38px;
    overflow: visible;
  }

  .lesson-studio .model-head .eyebrow {
    display: none;
  }

  .lesson-studio .model-head h2 {
    overflow: visible;
    overflow-wrap: anywhere;
    font-size: 15px;
  }

  .lesson-studio .formula-strip {
    order: 2;
    min-height: 34px;
    max-height: 34px;
    overflow-x: auto;
    overflow-y: hidden;
    white-space: nowrap;
  }

  .lesson-studio .model-feedback,
  .lesson-studio .course-controls {
    display: none;
  }

  .lesson-studio .visual-stage {
    order: 3;
    height: auto !important;
    min-height: 0;
    overflow: hidden;
  }

  .lesson-studio .visual-stage .equation-responsive-board,
  .lesson-studio .visual-stage .expression-lab,
  .lesson-studio .visual-stage .manipulative {
    max-height: 286px;
  }

  .lesson-studio .visual-stage .desktop-equation-balance {
    max-height: 220px;
  }

  .lesson-studio .course-prompt {
    min-height: 120px;
    max-height: 120px;
    grid-template-columns: minmax(0, 1fr) minmax(0, 244px);
    align-items: center;
    overflow: hidden;
    padding: 12px;
  }

  .lesson-studio .course-prompt h2 {
    margin-top: 4px;
    font-size: 18px;
    line-height: 1.14;
    overflow-wrap: anywhere;
  }

  .lesson-studio .course-prompt .feedback {
    font-size: 12px;
    line-height: 1.25;
  }

  .lesson-studio .choice-row {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 7px;
    min-width: 0;
  }

  .lesson-studio .choice-row button {
    min-height: 36px;
    padding: 6px 10px;
    font-size: 12px;
    line-height: 1.15;
  }

  .lesson-inspector {
    max-height: 510px;
    overflow: auto;
    scrollbar-width: thin;
  }

  .lesson-practice {
    max-height: 184px;
    overflow: auto;
    scrollbar-width: thin;
  }

  .lesson-mistake-panel {
    max-height: 184px;
    overflow: auto;
    scrollbar-width: thin;
  }
}

/* Course system cockpit: use the full desktop viewport after adding the system sidebar. */
@media (min-width: 1181px) {
  .course-system-shell {
    overflow: hidden;
  }

  .course-system-shell .lesson-studio-shell {
    display: flex;
    flex-direction: column;
    min-height: calc(100vh - 16px);
    overflow: hidden;
  }

  .lesson-studio-shell .course-nav {
    flex: 0 0 38px;
  }

  .lesson-studio-shell .course-hero {
    flex: 0 0 62px;
  }

  .lesson-dashboard-strip,
  .lesson-journey,
  .lesson-proofbar {
    flex: 0 0 auto;
  }

  .lesson-studio {
    flex: 0 0 calc(100vh - 134px);
    min-height: 0;
    height: calc(100vh - 134px);
    max-height: none;
    grid-template-columns: 128px minmax(0, 1fr) 276px;
    grid-template-rows: minmax(0, 1fr) 92px 68px;
    grid-template-areas:
      "steps main panel"
      "steps practice panel"
      "steps mistake panel";
    overflow: hidden;
  }

  .lesson-stepper {
    position: static;
    align-content: start;
    gap: 6px;
    max-height: none;
    height: 100%;
    overflow: auto;
    scrollbar-width: thin;
    padding: 8px;
  }

  .lesson-stepper a {
    position: relative;
    grid-template-columns: 26px minmax(0, 1fr);
    grid-template-rows: auto auto;
    min-height: 46px;
    gap: 1px 7px;
    border: 1px solid rgba(64, 111, 178, 0.1);
    background: rgba(255, 255, 255, 0.64);
    padding: 7px 8px 7px 6px;
  }

  .lesson-stepper b {
    grid-row: 1 / span 2;
    width: 24px;
    height: 24px;
    align-self: center;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9);
  }

  .lesson-stepper span {
    align-self: end;
    font-size: 12px;
    line-height: 1.12;
  }

  .lesson-stepper small {
    align-self: start;
    font-size: 9px;
    line-height: 1.1;
  }

  .lesson-stepper em {
    position: absolute;
    right: 6px;
    top: 6px;
    max-width: 48px;
    overflow: hidden;
    padding: 2px 5px;
    font-size: 8px;
    line-height: 1;
    text-overflow: ellipsis;
  }

  .lesson-stepper a.is-active,
  .lesson-stepper a[aria-current="step"] {
    border-color: rgba(31, 111, 229, 0.24);
    background:
      radial-gradient(circle at 12% 0%, rgba(255, 255, 255, 0.98), transparent 34%),
      linear-gradient(180deg, #f3f8ff, #eaf3ff);
    box-shadow: 0 10px 24px rgba(31, 111, 229, 0.12);
  }

  .lesson-stepper a.is-done {
    border-color: rgba(42, 166, 120, 0.2);
    background: rgba(237, 249, 243, 0.82);
  }

  .lesson-main {
    min-height: 0;
    grid-template-rows: minmax(278px, 1fr) 120px;
    overflow: hidden;
  }

  .lesson-studio .model-card {
    max-height: none;
    min-height: 0;
    overflow: hidden;
  }

  .lesson-studio .visual-stage {
    min-height: 220px;
    overflow: auto;
    scrollbar-width: thin;
  }

  .lesson-studio .visual-stage .equation-responsive-board,
  .lesson-studio .visual-stage .expression-lab,
  .lesson-studio .visual-stage .manipulative {
    max-height: 100%;
  }

  .lesson-studio .visual-stage .desktop-equation-balance {
    max-height: 280px;
  }

  .lesson-studio .visual-stage .model-caption {
    display: none;
  }

  .lesson-studio-shell .topbar,
  .lesson-studio-shell .prompt-card,
  .lesson-studio-shell .model-card,
  .lesson-studio-shell .mini-card,
  .lesson-studio-shell .lesson-panel,
  .lesson-studio-shell .practice-panel,
  .lesson-studio-shell .lesson-mistake-panel {
    animation: none !important;
    filter: none !important;
  }

  .lesson-studio-shell .prompt-card,
  .lesson-studio-shell .model-card,
  .lesson-studio-shell .mini-card,
  .lesson-studio-shell .practice-panel,
  .lesson-studio-shell .lesson-mistake-panel {
    backdrop-filter: none;
    background-color: rgba(255, 255, 255, 0.88);
  }

  .lesson-studio .course-prompt {
    min-height: 128px;
    max-height: 128px;
    grid-template-columns: minmax(0, 1fr) minmax(0, 360px);
    overflow-x: hidden;
    overflow-y: auto;
    padding: 12px;
    scrollbar-width: thin;
  }

  .lesson-inspector {
    max-height: none;
    height: 100%;
  }

  .lesson-practice {
    max-height: none;
    height: 100%;
  }

  .lesson-mistake-panel {
    max-height: none;
    height: 100%;
  }
}

@media (min-width: 1181px) {
  .lesson-studio .choice-row {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .lesson-studio .choice-row button,
  .lesson-studio .answer-options button {
    white-space: normal;
    overflow-wrap: anywhere;
  }

  .lesson-studio .expression-action-chip {
    min-width: 70px;
    padding-inline: 10px;
  }
}

/* Desktop practice card polish: keep transfer tasks readable in the cockpit row. */
@media (min-width: 1181px) {
  .lesson-practice {
    display: grid;
    grid-template-rows: auto minmax(0, 1fr);
    gap: 8px;
    overflow: hidden;
    padding: 10px;
  }

  .lesson-practice > div:first-child {
    display: flex;
    min-width: 0;
    align-items: baseline;
    justify-content: space-between;
    gap: 12px;
  }

  .lesson-practice .eyebrow {
    margin: 0;
  }

  .lesson-practice h2 {
    margin: 0;
    font-size: 15px;
    line-height: 1.16;
  }

  .practice-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
    min-height: 0;
    overflow: hidden;
  }

  .practice-card {
    min-width: 0;
    gap: 7px;
    border-color: rgba(42, 166, 120, 0.14);
    background:
      linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(246, 253, 250, 0.84));
    padding: 10px;
  }

  .practice-card-head {
    min-height: 22px;
  }

  .practice-card-head span,
  .practice-card-head em,
  .practice-question small {
    min-height: 20px;
    padding: 0 7px;
    font-size: 10px;
    line-height: 1;
  }

  .practice-question {
    gap: 5px;
  }

  .practice-question strong {
    font-size: 13px;
    line-height: 1.22;
  }

  .practice-question span,
  .practice-question small {
    display: none;
  }

  .practice-card .answer-options {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
    margin-top: 0;
  }

  .answer-options button {
    min-width: 0;
    min-height: 28px;
    padding: 4px 7px;
    font-size: 11px;
    line-height: 1.12;
  }

  .practice-diagnosis {
    grid-template-columns: minmax(0, 1fr);
    min-height: 26px;
    gap: 0;
    padding: 5px 8px;
    font-size: 11px;
    line-height: 1.12;
  }

  .practice-diagnosis:not(.right):not(.wrong) {
    display: none;
  }

  .practice-diagnosis b,
  .practice-diagnosis a {
    display: none;
  }

  .practice-diagnosis span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
}

/* Large desktop density: keep the lesson blocks connected like the reference cockpit. */
@media (min-width: 1181px) and (min-height: 850px) {
  .lesson-studio {
    grid-template-rows: 520px 174px 104px;
  }
}

/* Readability QA guard: course chips and controls need breathing room. */
@media (min-width: 1181px) {
  .lesson-studio .formula-strip {
    min-height: 40px;
    max-height: 42px;
    padding: 6px 8px;
  }

  .lesson-studio .formula-pill {
    display: inline-flex;
    min-width: 82px;
    min-height: 28px;
    justify-content: center;
    align-items: center;
    padding: 6px 11px;
    line-height: 1.15;
    white-space: nowrap;
  }

  .lesson-studio .model-head .ghost-button,
  .lesson-studio .ghost-button {
    min-width: 58px;
    min-height: 34px;
    padding: 7px 13px;
  }

  .lesson-studio .model-card {
    grid-template-rows: 42px 42px minmax(0, 1fr);
  }

  .lesson-main {
    grid-template-rows: minmax(282px, 1fr) 120px;
  }
}

.lesson-studio .formula-pill {
  min-width: 82px;
  min-height: 28px;
  text-align: center;
}

.lesson-neighbors a,
.lesson-action-board a,
.course-side-cta {
  min-width: 74px;
  min-height: 32px;
}

@media (max-width: 1180px) {
  .catalog-button strong {
    display: none;
  }

  .catalog-button {
    min-width: 230px;
    min-height: 46px;
  }
}

@media (min-width: 1181px) {
  .lesson-studio .model-head {
    min-height: 42px;
    max-height: 42px;
  }
}

/* Visual comfort QA: lesson text must breathe, not merely fit. */
@media (min-width: 1181px) {
  .lesson-studio-shell .course-nav {
    grid-template-columns: 34px minmax(0, 250px) 34px;
  }

  .lesson-studio-shell .catalog-button {
    min-width: 250px;
    padding-inline: 14px;
  }

  .lesson-inspector .mini-card {
    min-height: 68px;
    max-height: 118px;
    overflow: auto;
    padding: 12px 14px;
    scrollbar-width: thin;
  }

  .lesson-inspector .problem-card {
    min-height: 72px;
  }

  .neighbor-list {
    gap: 8px;
  }

  .lesson-neighbors a.neighbor-link,
  .neighbor-link {
    min-height: 76px;
    gap: 4px;
    padding: 10px 12px;
  }

  .neighbor-link strong {
    line-height: 1.24;
  }

  .course-side-cta {
    display: grid;
    place-items: center;
    min-height: 36px;
    padding-inline: 10px;
  }

  .complete-button {
    display: grid;
    min-height: 42px;
    place-items: center;
    padding: 8px 14px;
  }

  .lesson-studio .visual-stage .expression-action-chip {
    min-height: 30px;
    padding-block: 3px;
  }

  .lesson-studio .visual-stage .balance-step-panel button {
    min-height: 32px;
    padding-block: 3px;
  }

  .practice-card {
    overflow: auto;
    scrollbar-width: thin;
  }

  .answer-options button,
  .lesson-studio .answer-options button {
    min-width: 92px;
    min-height: 32px;
    padding: 6px 10px;
    overflow-wrap: anywhere;
    white-space: normal;
  }
}

/* Visual comfort QA: mobile and tablet controls need real touch height. */
.formula-pill,
.ghost-button,
#lessonActionLink {
  display: inline-grid;
  min-height: 34px;
  place-items: center;
  padding-top: 4px;
  padding-bottom: 4px;
}

#lessonActionLink {
  min-width: 82px;
  padding-inline: 12px;
}

@media (max-width: 1180px) {
  .formula-pill,
  .ghost-button,
  #lessonActionLink,
  .answer-options button {
    min-height: 36px;
  }
}

.formula-pill,
.lesson-studio .formula-pill {
  min-height: 34px !important;
  padding-top: 5px !important;
  padding-bottom: 5px !important;
}

.ghost-button,
#lessonActionLink {
  min-height: 36px !important;
  padding-top: 5px !important;
  padding-bottom: 5px !important;
}

.answer-options button,
.lesson-studio .answer-options button {
  min-width: 120px !important;
  min-height: 34px !important;
  padding: 7px 10px !important;
}

.formula-pill,
.lesson-studio .formula-pill {
  line-height: 1.22 !important;
}

.practice-card a,
.lesson-practice a,
a[href="#model"] {
  display: inline-grid !important;
  min-height: 36px !important;
  place-items: center !important;
  padding: 6px 12px !important;
}

.complete-button {
  padding: 8px 14px !important;
}

/* Visual comfort QA hard gate: controls used on every lesson page. */
.completion-evidence a,
.lesson-studio .completion-evidence a {
  display: inline-grid !important;
  min-height: 36px !important;
  place-items: center !important;
  padding: 6px 12px !important;
  line-height: 1.2 !important;
}

.practice-card .answer-options,
.lesson-studio .practice-card .answer-options {
  display: flex !important;
  overflow-x: auto !important;
  gap: 8px !important;
  scrollbar-width: thin;
}

.practice-card .answer-options button,
.lesson-studio .practice-card .answer-options button {
  flex: 0 0 160px !important;
  white-space: normal !important;
  line-height: 1.18 !important;
}

.direct-manipulation-cue {
  overflow: auto !important;
  scrollbar-width: thin;
}

.balance-step-panel button,
.lesson-studio .balance-step-panel button,
.lesson-studio .visual-stage .balance-step-panel button {
  min-height: 38px !important;
  padding: 8px 16px !important;
  line-height: 1.2 !important;
}

/* Reference-image polish: make the lesson page feel like a refined course cockpit. */
.course-system-shell {
  background:
    radial-gradient(circle at 18% 0%, rgba(191, 220, 255, 0.55), transparent 28%),
    linear-gradient(135deg, #e8f3ff 0%, #f6fbff 38%, #eef7ff 100%) !important;
}

.lesson-studio-shell .course-hero,
.lesson-studio .course-prompt,
.lesson-studio .model-card,
.lesson-studio .lesson-practice,
.lesson-studio .lesson-mistake-panel,
.lesson-inspector .mini-card,
.lesson-dashboard-strip article,
.lesson-proofbar article {
  border-color: rgba(60, 112, 190, 0.18) !important;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(247, 251, 255, 0.88)) !important;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.95),
    0 12px 28px rgba(51, 93, 146, 0.08) !important;
}

.lesson-studio .visual-stage {
  border-color: rgba(64, 124, 210, 0.2) !important;
  background:
    linear-gradient(rgba(31, 111, 229, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 111, 229, 0.045) 1px, transparent 1px),
    radial-gradient(circle at 18% 6%, rgba(255, 255, 255, 0.98), transparent 28%),
    linear-gradient(180deg, rgba(249, 252, 255, 0.98), rgba(235, 246, 255, 0.94)) !important;
  background-size: 24px 24px, 24px 24px, auto, auto !important;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.96),
    inset 0 -18px 40px rgba(31, 111, 229, 0.045),
    0 16px 34px rgba(50, 92, 145, 0.1) !important;
}

.lesson-stepper a span,
.lesson-dashboard-strip article span,
.lesson-proofbar article span,
.formula-pill,
.practice-card-head span {
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.72);
}

.lesson-studio .course-prompt strong,
.lesson-studio .model-head strong,
.practice-question strong {
  letter-spacing: 0 !important;
}

/* Cross-model teaching manipulatives: Guizang-like soft material, exact math geometry. */
.lesson-studio .manipulative {
  border-radius: 18px;
  padding: 18px;
  background:
    radial-gradient(circle at 18% 12%, rgba(255, 255, 255, 0.92), transparent 32%),
    linear-gradient(145deg, rgba(255, 255, 255, 0.7), rgba(230, 243, 255, 0.54));
}

.lesson-studio .fraction-board,
.lesson-studio .bar-board,
.lesson-studio .percent-board {
  border-radius: 18px;
  padding: 16px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.86), rgba(246, 251, 255, 0.72));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.92),
    0 14px 28px rgba(51, 93, 146, 0.09);
}

.lesson-studio .fraction-row {
  border-color: rgba(36, 86, 150, 0.6);
  border-radius: 16px;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.95),
    0 12px 24px rgba(45, 115, 214, 0.12);
}

.lesson-studio .fraction-part {
  background: linear-gradient(180deg, #ffffff, #f1f7ff);
}

.lesson-studio .fraction-part.is-active {
  background:
    radial-gradient(circle at 28% 20%, rgba(255, 255, 255, 0.84), transparent 34%),
    linear-gradient(145deg, #b9ece4, #5fc4b2);
}

.lesson-studio .percent-cell,
.lesson-studio .array-cell,
.lesson-studio .touch-block,
.lesson-studio .quantity-bar {
  border-color: rgba(45, 115, 214, 0.35);
  border-radius: 10px;
  background:
    radial-gradient(circle at 28% 18%, rgba(255, 255, 255, 0.9), transparent 36%),
    linear-gradient(145deg, #ffffff, #dcecff);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.9),
    0 8px 18px rgba(45, 115, 214, 0.12);
}

.lesson-studio .percent-cell.is-active {
  border-color: rgba(40, 123, 115, 0.48);
  background:
    radial-gradient(circle at 28% 18%, rgba(255, 255, 255, 0.78), transparent 36%),
    linear-gradient(145deg, #b9ece4, #5fc4b2);
}

.lesson-studio .model-caption {
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.74);
  padding: 8px 14px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.92);
}

.lesson-studio .visual-stage svg.geometry-direct-model,
.lesson-studio .visual-stage svg[aria-label="坐标平面"],
.lesson-studio .visual-stage svg[aria-label="表格图像公式三联视图"] {
  overflow: visible;
  filter: drop-shadow(0 14px 22px rgba(50, 92, 145, 0.1));
}

.geometry-surface {
  fill: rgba(255, 255, 255, 0.72);
  stroke: rgba(45, 115, 214, 0.2);
  stroke-width: 2;
}

.geometry-title {
  fill: #143457;
  font-size: 22px;
  font-weight: 900;
}

.geometry-label {
  fill: #155bc5;
  font-size: 22px;
  font-weight: 900;
}

.geometry-note {
  fill: #49677d;
  font-size: 16px;
  font-weight: 780;
}

.geometry-line,
.geometry-base {
  stroke: #2d73d6;
  stroke-width: 6;
  stroke-linecap: round;
}

.geometry-point {
  fill: #fff;
  stroke: #2d73d6;
  stroke-width: 5;
}

.geometry-html-model {
  display: grid;
  width: min(100%, 760px);
  min-height: 326px;
  gap: 10px;
  border: 1px solid rgba(45, 115, 214, 0.14);
  border-radius: 8px;
  background:
    radial-gradient(circle at 18% 0%, rgba(255, 255, 255, 0.96), transparent 36%),
    radial-gradient(circle at 82% 78%, rgba(185, 236, 228, 0.42), transparent 42%),
    linear-gradient(145deg, rgba(249, 254, 253, 0.94), rgba(235, 247, 244, 0.9));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.88), 0 18px 44px rgba(37, 55, 78, 0.1);
  padding: 14px;
}

.geometry-html-head {
  display: grid;
  gap: 5px;
  text-align: center;
}

.geometry-html-head span {
  color: #287b73;
  font-size: 12px;
  font-weight: 900;
}

.geometry-html-head strong {
  color: #17384a;
  font-size: 24px;
  line-height: 1.15;
}

.line-kind-board {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  min-width: 0;
}

.line-kind-card {
  display: grid;
  gap: 12px;
  align-content: center;
  min-width: 0;
  min-height: 132px;
  border: 1px solid rgba(45, 115, 214, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  color: #17384a;
  cursor: pointer;
  padding: 12px;
  text-align: center;
  box-shadow: 0 14px 30px rgba(37, 55, 78, 0.07);
  transition: transform 180ms ease, border-color 180ms ease, background 180ms ease;
}

.line-kind-card:hover,
.line-kind-card:focus-visible,
.line-kind-card.is-active {
  border-color: rgba(45, 115, 214, 0.46);
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.94), rgba(234, 244, 255, 0.86));
  transform: translateY(-2px);
  outline: none;
}

.line-kind-name {
  font-size: 20px;
  font-weight: 950;
}

.line-kind-meta {
  color: #55706f;
  font-size: 14px;
  font-weight: 900;
}

.line-mini {
  position: relative;
  display: block;
  width: min(100%, 190px);
  height: 50px;
  margin: 0 auto;
}

.line-mini i {
  position: absolute;
  left: 15%;
  right: 15%;
  top: 24px;
  height: 7px;
  border-radius: 999px;
  background: #2d73d6;
  box-shadow: 0 10px 20px rgba(45, 115, 214, 0.18);
}

.line-mini b,
.line-mini em {
  position: absolute;
  top: 15px;
  width: 24px;
  height: 24px;
  border: 5px solid #2d73d6;
  border-radius: 50%;
  background: #fff;
}

.line-mini b { left: calc(15% - 11px); }
.line-mini em { right: calc(15% - 11px); }

.line-mini-ray em,
.line-mini-line b,
.line-mini-line em {
  top: 13px;
  width: 0;
  height: 0;
  border-top: 13px solid transparent;
  border-bottom: 13px solid transparent;
  border-left: 22px solid #2d73d6;
  border-right: 0;
  border-radius: 0;
  background: transparent;
}

.line-mini-line b {
  transform: rotate(180deg);
}

.line-mini-ray i { right: 6%; }
.line-mini-ray em { right: 3%; }
.line-mini-line i {
  left: 6%;
  right: 6%;
}
.line-mini-line b { left: 3%; }
.line-mini-line em { right: 3%; }

.line-kind-result {
  display: grid;
  gap: 5px;
  justify-items: center;
  border: 1px solid rgba(18, 160, 133, 0.18);
  border-radius: 8px;
  background: rgba(234, 247, 242, 0.82);
  padding: 10px 12px;
  text-align: center;
}

.line-kind-result span {
  color: #287b73;
  font-size: 14px;
  font-weight: 950;
}

.line-kind-result strong {
  color: #17384a;
  font-size: 18px;
  line-height: 1.25;
}

.line-kind-result small {
  color: #55706f;
  font-weight: 850;
}

.geometry-handle {
  cursor: grab;
  outline: none;
  filter: drop-shadow(0 12px 18px rgba(45, 115, 214, 0.22));
}

.geometry-handle:active {
  cursor: grabbing;
}

.geometry-handle:focus-visible circle:first-child {
  stroke: #f4bd45;
  stroke-width: 7;
}

.stat-html-model {
  display: grid;
  width: min(100%, 760px);
  min-height: 326px;
  gap: 12px;
  border: 1px solid rgba(45, 115, 214, 0.14);
  border-radius: 8px;
  background:
    radial-gradient(circle at 20% 2%, rgba(255, 255, 255, 0.96), transparent 36%),
    radial-gradient(circle at 86% 76%, rgba(244, 189, 69, 0.18), transparent 38%),
    linear-gradient(145deg, rgba(249, 254, 253, 0.94), rgba(237, 246, 255, 0.88));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9), 0 18px 44px rgba(37, 55, 78, 0.09);
  padding: 14px;
}

.stat-html-head {
  display: grid;
  gap: 5px;
  text-align: center;
}

.stat-html-head span {
  color: #287b73;
  font-size: 12px;
  font-weight: 900;
}

.stat-html-head strong {
  color: #17384a;
  font-size: 24px;
  line-height: 1.15;
}

.stat-choice-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.stat-choice {
  display: grid;
  gap: 6px;
  min-width: 0;
  min-height: 74px;
  border: 1px solid rgba(45, 115, 214, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  color: #17384a;
  cursor: pointer;
  padding: 10px;
  text-align: center;
  box-shadow: 0 12px 26px rgba(37, 55, 78, 0.06);
}

.stat-choice:hover,
.stat-choice:focus-visible,
.stat-choice.is-active {
  border-color: rgba(18, 160, 133, 0.42);
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.96), rgba(234, 247, 242, 0.84));
  outline: none;
}

.stat-choice b {
  font-size: 15px;
  line-height: 1.25;
}

.stat-choice span {
  color: #287b73;
  font-size: 13px;
  font-weight: 950;
}

.data-check-board {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.data-check {
  display: grid;
  justify-items: center;
  gap: 7px;
  border: 1px solid rgba(69, 102, 116, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  padding: 12px 8px;
}

.data-check i {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 50%;
  font-style: normal;
  font-weight: 950;
}

.data-check.is-good i {
  background: #eaf7f2;
  color: #0f766e;
}

.data-check.is-bad i {
  background: #fff4d6;
  color: #9b6b12;
}

.data-check span {
  color: #17384a;
  font-size: 13px;
  font-weight: 900;
  text-align: center;
}

.chart-choice-board {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(220px, 0.8fr);
  gap: 12px;
  align-items: center;
}

.chart-choice-board svg {
  width: 100%;
  min-height: 120px;
  border: 1px solid rgba(45, 115, 214, 0.12);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  padding: 8px;
}

.stat-result {
  display: grid;
  gap: 6px;
  justify-items: center;
  border: 1px solid rgba(18, 160, 133, 0.18);
  border-radius: 8px;
  background: rgba(234, 247, 242, 0.82);
  padding: 12px;
  text-align: center;
}

.stat-result strong {
  color: #0f766e;
  font-size: 21px;
  font-weight: 950;
}

.stat-result span {
  color: #55706f;
  font-weight: 850;
}

@media (max-width: 640px) {
  .geometry-html-model {
    min-height: 0;
    gap: 12px;
    padding: 12px;
  }

  .geometry-html-head strong {
    font-size: 19px;
  }

  .line-kind-board {
    grid-template-columns: 1fr;
    gap: 9px;
  }

  .line-kind-card {
    grid-template-columns: 72px minmax(0, 1fr) 82px;
    align-items: center;
    min-height: 88px;
    padding: 10px;
    text-align: left;
  }

  .line-kind-name {
    font-size: 18px;
  }

  .line-mini {
    width: 100%;
    height: 46px;
  }

  .line-kind-meta {
    font-size: 12px;
    text-align: right;
  }

  .line-kind-result strong {
    font-size: 17px;
  }

  .stat-html-model {
    min-height: 0;
    gap: 10px;
    padding: 12px;
  }

  .stat-html-head strong {
    font-size: 19px;
  }

  .stat-choice-row,
  .data-check-board,
  .chart-choice-board {
    grid-template-columns: 1fr;
  }

  .stat-choice {
    min-height: 62px;
  }

  .data-check-board {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .chart-choice-board svg {
    min-height: 104px;
  }
}

.geometry-shape {
  fill: rgba(255, 255, 255, 0.82);
  stroke: #17384a;
  stroke-width: 5;
  stroke-linejoin: round;
}

.geometry-shape.is-target {
  fill: rgba(185, 236, 228, 0.42);
  stroke: #2aa678;
  stroke-dasharray: 8 8;
}

.geometry-cut,
.geometry-arrow {
  fill: none;
  stroke: #2aa678;
  stroke-width: 5;
  stroke-linecap: round;
  stroke-dasharray: 8 8;
}

.geometry-shadow-rect {
  fill: rgba(45, 115, 214, 0.08);
  stroke: rgba(45, 115, 214, 0.18);
  stroke-width: 2;
}

.bar-model-board,
.data-sort-board,
.probability-board {
  width: min(680px, 100%);
  border-radius: 22px;
  padding: 18px;
  background:
    radial-gradient(circle at 18% 10%, rgba(255, 255, 255, 0.9), transparent 32%),
    linear-gradient(145deg, rgba(255, 255, 255, 0.84), rgba(236, 247, 255, 0.74));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.95),
    0 16px 30px rgba(51, 93, 146, 0.1);
}

.bar-model-board {
  display: grid;
  gap: 14px;
}

.bar-model-row {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  align-items: center;
  gap: 12px;
}

.bar-model-row b,
.data-group b,
.probability-result b {
  color: #155bc5;
  font-size: 13px;
  font-weight: 900;
}

.bar-model-row span {
  display: grid;
  width: max(120px, var(--bar));
  min-height: 44px;
  place-items: center;
  border: 2px solid rgba(45, 115, 214, 0.42);
  border-radius: 12px;
  background:
    radial-gradient(circle at 20% 16%, rgba(255, 255, 255, 0.82), transparent 30%),
    linear-gradient(90deg, #f8fbff, #cfe4ff);
  color: #17384a;
  font-weight: 900;
}

.bar-model-row.is-unknown span {
  border-color: rgba(42, 166, 120, 0.46);
  background:
    radial-gradient(circle at 20% 16%, rgba(255, 255, 255, 0.82), transparent 30%),
    linear-gradient(90deg, #f8fffd, #b9ece4);
}

.data-sort-board {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.data-group {
  display: grid;
  min-height: 142px;
  align-content: space-between;
  gap: 10px;
  border: 1px solid rgba(45, 115, 214, 0.14);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.62);
  padding: 12px;
}

.data-group div {
  display: grid;
  grid-template-columns: repeat(5, 18px);
  gap: 7px;
}

.data-group span,
.probability-bag span {
  width: 18px;
  height: 18px;
  border-radius: 999px;
  background:
    radial-gradient(circle at 28% 24%, rgba(255, 255, 255, 0.9), transparent 34%),
    var(--dot, #5b9cff);
  box-shadow: 0 7px 14px rgba(51, 93, 146, 0.14);
}

.data-group em {
  color: #17384a;
  font-size: 22px;
  font-style: normal;
  font-weight: 950;
}

.probability-board {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 22px;
  align-items: center;
}

.probability-bag {
  display: grid;
  grid-template-columns: repeat(5, 28px);
  justify-content: center;
  gap: 12px;
  border: 2px solid rgba(45, 115, 214, 0.22);
  border-radius: 28px 28px 18px 18px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.72), rgba(221, 235, 255, 0.56));
  padding: 28px 18px 20px;
}

.probability-bag span {
  width: 28px;
  height: 28px;
  --dot: #f4bd45;
}

.probability-bag span.is-hit {
  --dot: #f4766f;
}

.probability-result {
  display: grid;
  gap: 10px;
}

.probability-result div {
  display: grid;
  grid-template-columns: 90px minmax(0, 1fr);
  align-items: center;
  min-height: 44px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.66);
  padding: 8px 12px;
}

.probability-result strong {
  color: #17384a;
  font-size: 22px;
  font-weight: 950;
}

.circle-disc {
  fill: rgba(255, 255, 255, 0.78);
  stroke: #17384a;
  stroke-width: 5;
  filter: drop-shadow(0 16px 22px rgba(51, 93, 146, 0.12));
}

.radius-line,
.diameter-line {
  stroke: #2d73d6;
  stroke-width: 5;
  stroke-linecap: round;
}

.diameter-line {
  stroke: rgba(42, 166, 120, 0.66);
  stroke-dasharray: 10 8;
}

.axis-line {
  stroke: rgba(23, 56, 74, 0.68);
  stroke-width: 2;
}

.function-curve {
  fill: none;
  stroke: #2d73d6;
  stroke-width: 6;
  stroke-linecap: round;
}

.symmetry-line {
  stroke: #2aa678;
  stroke-width: 4;
  stroke-dasharray: 8 8;
}

.vertex-dot {
  fill: #f0a94f;
  stroke: #fff;
  stroke-width: 4;
}

@media (max-width: 640px) {
  .bar-model-board,
  .data-sort-board,
  .probability-board {
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    border-radius: 18px;
    padding: 12px;
  }

  .bar-model-row {
    grid-template-columns: 42px minmax(0, 1fr);
    gap: 8px;
  }

  .bar-model-row span {
    width: min(100%, max(72px, var(--bar)));
    min-height: 38px;
    padding: 0 8px;
    box-sizing: border-box;
    font-size: 13px;
  }

  .data-sort-board {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
  }

  .data-group {
    min-width: 0;
    min-height: 118px;
    padding: 9px 7px;
    gap: 8px;
  }

  .data-group b,
  .probability-result b {
    min-width: 0;
    overflow-wrap: anywhere;
    font-size: 12px;
    line-height: 1.15;
  }

  .data-group div {
    grid-template-columns: repeat(4, 13px);
    gap: 5px;
  }

  .data-group span,
  .probability-bag span {
    width: 13px;
    height: 13px;
  }

  .data-group em {
    font-size: 18px;
  }

  .probability-board {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .probability-bag {
    grid-template-columns: repeat(5, 22px);
    gap: 8px;
    padding: 16px 10px 12px;
    border-radius: 22px 22px 16px 16px;
  }

  .probability-bag span {
    width: 22px;
    height: 22px;
  }

  .probability-result {
    gap: 8px;
  }

  .probability-result div {
    grid-template-columns: minmax(0, 1fr) auto;
    min-height: 38px;
    padding: 7px 10px;
    gap: 10px;
  }

  .probability-result strong {
    font-size: 18px;
  }
}

/* Classroom clean pass: align the lesson page with the reference cockpit without adding clutter. */
.course-system-shell {
  background:
    linear-gradient(180deg, #f4f9fb 0%, #edf6fb 50%, #f8f5ef 100%);
}

.course-sidebar,
.lesson-studio-shell .course-nav,
.lesson-studio-shell .course-hero,
.lesson-stepper,
.lesson-studio .model-card,
.lesson-studio .course-prompt,
.lesson-inspector .mini-card,
.lesson-practice,
.lesson-mistake-panel .mini-card {
  border-color: rgba(43, 83, 124, 0.11) !important;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(248, 252, 255, 0.86)) !important;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.9),
    0 14px 34px rgba(43, 77, 105, 0.075) !important;
}

.lesson-studio-shell .course-nav {
  min-height: 52px;
  border-radius: 16px;
}

.lesson-studio-shell .course-hero {
  border-radius: 16px;
  padding: 12px 16px !important;
}

.lesson-studio-shell .course-hero h1 {
  font-size: 28px !important;
  line-height: 1.05 !important;
}

.lesson-studio-shell .top-focus span {
  border-color: rgba(60, 155, 143, 0.18) !important;
  background: rgba(255, 255, 255, 0.7) !important;
  color: #287b73 !important;
}

.lesson-stepper {
  gap: 10px !important;
  padding: 10px !important;
}

.lesson-stepper a {
  border-color: rgba(43, 83, 124, 0.09) !important;
  background: rgba(255, 255, 255, 0.66) !important;
  box-shadow: none !important;
}

.lesson-stepper a.is-active,
.lesson-stepper a[aria-current="step"] {
  border-color: rgba(31, 111, 229, 0.24) !important;
  background: linear-gradient(180deg, #f1f7ff, #e7f1ff) !important;
}

.lesson-stepper b {
  box-shadow: none !important;
}

.lesson-studio .model-card {
  border-radius: 18px !important;
  overflow: hidden !important;
}

.lesson-studio .model-head {
  margin: 10px 10px 0 !important;
  border-radius: 14px !important;
  background:
    linear-gradient(135deg, rgba(235, 247, 255, 0.96), rgba(231, 249, 244, 0.92)) !important;
  box-shadow: none !important;
}

.lesson-studio .model-head h2 {
  color: #172033 !important;
  font-size: 18px !important;
  line-height: 1.24 !important;
}

.lesson-studio .formula-strip {
  border-color: rgba(43, 83, 124, 0.09) !important;
  background: rgba(255, 255, 255, 0.72) !important;
}

.lesson-studio .formula-pill {
  background: rgba(31, 111, 229, 0.08) !important;
  color: #155bc5 !important;
}

.lesson-studio .formula-pill.green {
  background: rgba(60, 155, 143, 0.12) !important;
  color: #287b73 !important;
}

.lesson-studio .model-feedback {
  color: #53667d !important;
}

.lesson-studio .visual-stage {
  border-color: rgba(31, 111, 229, 0.13) !important;
  background:
    linear-gradient(rgba(31, 111, 229, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 111, 229, 0.025) 1px, transparent 1px),
    radial-gradient(circle at 50% 16%, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0) 34%),
    linear-gradient(180deg, #fbfdff 0%, #f3f9ff 58%, #eef7f9 100%) !important;
  background-size: 28px 28px, 28px 28px, auto, auto !important;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.96),
    inset 0 -28px 60px rgba(47, 111, 214, 0.045) !important;
}

.lesson-studio .visual-stage::before {
  opacity: 0.28 !important;
}

.lesson-studio .course-prompt {
  border-radius: 16px !important;
}

.lesson-studio .course-prompt h2 {
  font-size: 20px !important;
  line-height: 1.32 !important;
}

.lesson-studio .choice-row button,
.lesson-studio .answer-options button {
  border-color: rgba(43, 83, 124, 0.1) !important;
  background: rgba(255, 255, 255, 0.74) !important;
}

.lesson-inspector {
  gap: 10px !important;
}

.lesson-inspector .mini-card {
  border-radius: 16px !important;
  padding: 13px !important;
}

.lesson-inspector .problem-card {
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(246, 250, 255, 0.88)) !important;
}

.lesson-inspector .mini-card .eyebrow {
  color: #1769e0 !important;
}

.lesson-inspector .mini-card h3 {
  color: #172033 !important;
  font-size: 17px !important;
}

.lesson-inspector .mini-card p,
.lesson-inspector .mini-card li {
  color: #34465d !important;
}

.lesson-practice {
  border-radius: 18px !important;
  background:
    linear-gradient(180deg, rgba(250, 255, 253, 0.96), rgba(238, 250, 246, 0.88)) !important;
}

.lesson-mistake-panel .mistake-card {
  background:
    linear-gradient(180deg, rgba(255, 252, 246, 0.96), rgba(255, 245, 226, 0.9)) !important;
}

@media (max-width: 760px) {
  .lesson-studio-shell .course-hero h1 {
    font-size: 24px !important;
  }

  .lesson-stepper {
    padding: 8px !important;
  }

  .lesson-studio .model-head h2,
  .lesson-studio .course-prompt h2 {
    font-size: 18px !important;
  }
}

/* Lesson cockpit pass: make each knowledge page feel like a single focused studio. */
@media (min-width: 1181px) {
  .course-system-shell {
    background:
      radial-gradient(circle at 80% 8%, rgba(105, 171, 228, 0.18), transparent 28%),
      linear-gradient(180deg, #edf7ff 0%, #f5fafb 52%, #f8f5ef 100%) !important;
  }

  .lesson-studio-shell {
    gap: 10px !important;
  }

  .lesson-studio-shell .course-nav {
    min-height: 48px !important;
    max-width: 360px !important;
    justify-self: center !important;
    padding: 5px !important;
    background: rgba(255, 255, 255, 0.74) !important;
  }

  .lesson-studio-shell .catalog-button {
    min-height: 38px !important;
    border-radius: 12px !important;
  }

  .lesson-studio-shell .catalog-button strong {
    display: none !important;
  }

  .lesson-studio-shell .course-hero {
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) auto !important;
    min-height: 72px !important;
    padding: 12px 18px !important;
    border-radius: 20px !important;
  }

  .lesson-studio-shell .course-hero h1 {
    font-size: 30px !important;
  }

  .lesson-studio-shell .course-hero .top-focus {
    gap: 8px !important;
  }

  .lesson-studio {
    grid-template-columns: 126px minmax(0, 1fr) 286px !important;
    grid-template-rows: minmax(0, 520px) 174px auto !important;
    gap: 10px !important;
    max-height: none !important;
    overflow: visible !important;
  }

  .lesson-stepper {
    grid-row: 1 / span 3 !important;
    align-self: stretch !important;
    align-content: start !important;
    border-radius: 18px !important;
    padding: 10px !important;
  }

  .lesson-stepper a {
    min-height: 48px !important;
    border-radius: 12px !important;
    grid-template-columns: 30px minmax(0, 1fr) !important;
    gap: 8px !important;
  }

  .lesson-stepper b {
    width: 26px !important;
    height: 26px !important;
  }

  .lesson-main {
    display: grid !important;
    grid-template-rows: 82px minmax(0, 452px) !important;
    gap: 10px !important;
    min-height: 0 !important;
  }

  .lesson-main .course-prompt {
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) minmax(340px, 0.88fr) !important;
    align-items: center !important;
    position: static !important;
    transform: none !important;
    z-index: auto !important;
    min-height: 82px !important;
    max-height: 82px !important;
    padding: 10px 12px !important;
    overflow: hidden !important;
  }

  .lesson-main .course-prompt .eyebrow {
    margin: 0 0 4px !important;
  }

  .lesson-main .course-prompt h2 {
    font-size: 18px !important;
    line-height: 1.24 !important;
  }

  .lesson-main .course-prompt .choice-row {
    display: grid !important;
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 8px !important;
  }

  .lesson-main .course-prompt .choice-row button {
    min-height: 36px !important;
    border-radius: 12px !important;
    padding: 6px 10px !important;
  }

  .lesson-main .course-prompt .feedback {
    display: none !important;
  }

  .lesson-studio .model-card {
    min-height: 452px !important;
    max-height: 452px !important;
    display: grid !important;
    grid-template-rows: 64px 34px 28px minmax(0, 266px) 46px !important;
    border-radius: 20px !important;
  }

  .lesson-studio .model-head {
    min-height: 54px !important;
    margin: 10px 10px 0 !important;
  }

  .lesson-studio .model-head h2 {
    font-size: 19px !important;
  }

  .lesson-studio .formula-strip {
    min-height: 34px !important;
    margin: 0 10px !important;
  }

  .lesson-studio .model-feedback {
    min-height: 24px !important;
    margin: 0 12px !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-studio .visual-stage {
    min-height: 266px !important;
    margin: 0 10px !important;
    border-radius: 18px !important;
    padding-top: 12px !important;
  }

  .lesson-studio .course-controls {
    min-height: 42px !important;
    margin: 0 10px 10px !important;
  }

  .lesson-inspector {
    grid-row: 1 / span 1 !important;
    max-height: 520px !important;
    overflow: auto !important;
  }

  .lesson-practice {
    grid-column: 2 / span 1 !important;
    grid-row: 2 !important;
    min-height: 174px !important;
    max-height: 174px !important;
    overflow: hidden !important;
  }

  .lesson-practice .transfer-list {
    display: grid !important;
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 8px !important;
  }

  .lesson-mistake-panel {
    grid-column: 2 / span 2 !important;
    grid-row: 3 !important;
  }
}

/* Lesson QA fit pass 2026-07-19: keep formula chips and prompt text inside their own panels. */
@media (min-width: 1181px) {
  .lesson-studio {
    grid-template-rows: minmax(0, 548px) 174px auto !important;
  }

  .lesson-main {
    grid-template-rows: 108px minmax(0, 454px) !important;
  }

  .lesson-main .course-prompt {
    min-height: 108px !important;
    max-height: 108px !important;
    align-content: center !important;
  }

  .lesson-main .course-prompt h2 {
    font-size: 17px !important;
    line-height: 1.18 !important;
    margin: 0 !important;
  }

  .lesson-main .course-prompt .choice-row button {
    min-height: 34px !important;
    padding: 5px 8px !important;
  }

  .lesson-studio .model-card {
    min-height: 454px !important;
    max-height: 454px !important;
    grid-template-rows: 64px 42px 28px minmax(0, 258px) 46px !important;
  }

  .lesson-studio .formula-strip {
    min-height: 42px !important;
    height: 42px !important;
    align-items: center !important;
    overflow: visible !important;
  }

  .lesson-studio .formula-pill {
    min-height: 30px !important;
    padding: 6px 12px !important;
    line-height: 1.25 !important;
  }

  .lesson-studio .visual-stage {
    min-height: 258px !important;
  }

  .lesson-inspector {
    max-height: 548px !important;
  }
}

/* Reference course diagnostics pass 2026-07-19: make practice and error repair read like a system panel. */
@media (min-width: 1181px) {
  .lesson-practice {
    grid-column: 2 / span 2 !important;
    grid-row: 2 !important;
    min-height: 174px !important;
    max-height: 174px !important;
    display: grid !important;
    grid-template-columns: 180px minmax(0, 1fr) !important;
    align-items: stretch !important;
    gap: 12px !important;
    padding: 12px !important;
    border: 1px solid rgba(43, 117, 183, 0.13) !important;
    background:
      radial-gradient(circle at 90% 0%, rgba(47, 111, 214, 0.11), transparent 30%),
      linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(238, 250, 246, 0.88)) !important;
    box-shadow:
      inset 0 1px 0 rgba(255, 255, 255, 0.9),
      0 18px 38px rgba(39, 77, 111, 0.07) !important;
  }

  .lesson-practice > div:first-child {
    display: grid !important;
    align-content: center !important;
    gap: 8px !important;
    min-width: 0 !important;
  }

  .lesson-practice h2 {
    font-size: 18px !important;
    line-height: 1.18 !important;
  }

  .lesson-practice .practice-list,
  .lesson-practice .transfer-list {
    display: grid !important;
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 10px !important;
    min-height: 0 !important;
  }

  .lesson-practice .practice-card,
  .lesson-practice .transfer-card {
    min-height: 126px !important;
    border-radius: 14px !important;
    background: rgba(255, 255, 255, 0.74) !important;
  }

  .lesson-mistake-panel {
    grid-column: 2 / span 2 !important;
    grid-row: 3 !important;
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) 220px !important;
    align-items: stretch !important;
    gap: 12px !important;
  }

  .lesson-mistake-panel .mistake-card {
    min-height: 72px !important;
    border-radius: 16px !important;
    padding: 12px 14px !important;
  }

  .lesson-mistake-panel .complete-button {
    min-height: 72px !important;
    align-self: stretch !important;
    border-radius: 16px !important;
    box-shadow: 0 18px 34px rgba(31, 111, 229, 0.16) !important;
  }

  .lesson-mistake-panel .completion-evidence {
    grid-column: 1 / -1 !important;
    min-height: 34px !important;
    border-radius: 12px !important;
  }
}

/* Reference course studio fit 2026-07-19: no prompt/model overlap, tighter first screen. */
@media (min-width: 1181px) {
  .lesson-studio {
    grid-template-rows: 456px 174px auto !important;
  }

  .lesson-main {
    grid-template-rows: 86px 360px !important;
    gap: 10px !important;
    height: 456px !important;
    max-height: 456px !important;
    overflow: visible !important;
  }

  .lesson-main .course-prompt {
    order: 0 !important;
    min-height: 86px !important;
    max-height: 86px !important;
    grid-row: 1 !important;
    padding: 10px 12px !important;
    overflow: hidden !important;
  }

  .lesson-studio .model-card {
    order: 0 !important;
    grid-row: 2 !important;
    min-height: 360px !important;
    max-height: 360px !important;
    grid-template-rows: 52px 34px 24px minmax(0, 204px) 36px !important;
    overflow: hidden !important;
  }

  .lesson-studio .model-head {
    min-height: 44px !important;
    margin: 8px 10px 0 !important;
  }

  .lesson-studio .model-head h2 {
    font-size: 18px !important;
    line-height: 1.2 !important;
  }

  .lesson-studio .formula-strip {
    min-height: 34px !important;
    height: 34px !important;
    margin: 0 10px !important;
  }

  .lesson-studio .model-feedback {
    min-height: 22px !important;
    margin: 0 12px !important;
    font-size: 11px !important;
  }

  .lesson-studio .visual-stage {
    min-height: 204px !important;
    height: 204px !important;
    margin: 0 10px !important;
    padding-top: 8px !important;
  }

  .lesson-studio .course-controls {
    min-height: 34px !important;
    margin: 0 10px 8px !important;
  }

  .lesson-inspector {
    max-height: 456px !important;
  }
}

/* Lesson QA height correction 2026-07-19: keep prediction text and formula chips readable. */
@media (min-width: 1181px) {
  .lesson-studio {
    grid-template-rows: 478px 174px auto !important;
  }

  .lesson-main {
    grid-template-rows: 100px 368px !important;
    height: 478px !important;
    max-height: 478px !important;
  }

  .lesson-main .course-prompt {
    min-height: 100px !important;
    max-height: 100px !important;
  }

  .lesson-main .course-prompt h2 {
    font-size: 16px !important;
    line-height: 1.2 !important;
  }

  .lesson-studio .model-card {
    min-height: 368px !important;
    max-height: 368px !important;
    grid-template-rows: 52px 42px 24px minmax(0, 214px) 36px !important;
  }

  .lesson-studio .formula-strip {
    min-height: 42px !important;
    height: 42px !important;
    align-items: center !important;
    overflow: visible !important;
  }

  .lesson-studio .visual-stage {
    min-height: 214px !important;
    height: 214px !important;
  }

  .lesson-inspector {
    max-height: 478px !important;
  }
}

/* Unified course header 2026-07-19: keep lesson title, status, and navigation in one product panel. */
@media (min-width: 1181px) {
  .lesson-studio-shell .course-hero {
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) auto 214px !important;
    align-items: center !important;
    gap: 10px !important;
    min-height: 72px !important;
    padding: 12px 14px 12px 18px !important;
    border-radius: 20px !important;
    overflow: visible !important;
  }

  .lesson-studio-shell .course-hero > div:first-child {
    min-width: 0 !important;
  }

  .lesson-studio-shell .course-hero h1 {
    max-width: 640px !important;
    min-height: 38px !important;
    line-height: 1.16 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-studio-shell .course-hero .top-focus {
    display: flex !important;
    flex-wrap: nowrap !important;
    justify-content: end !important;
    gap: 8px !important;
    min-width: 0 !important;
  }

  .lesson-studio-shell .course-hero .top-focus span {
    min-height: 28px !important;
    padding: 5px 8px !important;
    border-radius: 999px !important;
    white-space: nowrap !important;
  }

  .lesson-studio-shell .course-nav {
    position: static !important;
    top: auto !important;
    z-index: auto !important;
    display: grid !important;
    grid-template-columns: 34px minmax(0, 132px) 34px !important;
    gap: 6px !important;
    justify-content: end !important;
    width: 214px !important;
    max-width: none !important;
    min-height: 40px !important;
    margin: 0 !important;
    padding: 4px !important;
    border-radius: 16px !important;
    border: 1px solid rgba(43, 83, 124, 0.09) !important;
    background: rgba(255, 255, 255, 0.64) !important;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.78) !important;
  }

  .lesson-studio-shell .course-nav .nav-button {
    width: 34px !important;
    min-height: 34px !important;
    border-radius: 12px !important;
    font-size: 18px !important;
    box-shadow: none !important;
  }

  .lesson-studio-shell .catalog-button {
    min-width: 0 !important;
    min-height: 34px !important;
    border-radius: 12px !important;
    padding: 6px 12px !important;
    box-shadow: none !important;
  }

  .lesson-studio-shell .catalog-button span {
    font-size: 12px !important;
    color: #344f63 !important;
    white-space: nowrap !important;
  }

  .lesson-studio-shell .catalog-button strong {
    display: none !important;
  }
}

@media (max-width: 1180px) {
  .lesson-studio-shell .course-hero {
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) auto !important;
    gap: 10px !important;
    align-items: center !important;
  }

  .lesson-studio-shell .course-hero .top-focus {
    justify-self: end !important;
  }

  .lesson-studio-shell .course-nav {
    grid-column: 1 / -1 !important;
    grid-row: 1 !important;
    position: static !important;
    display: grid !important;
    grid-template-columns: 44px minmax(0, 1fr) 44px !important;
    gap: 8px !important;
    width: 100% !important;
    margin: 0 0 6px !important;
    padding: 0 !important;
    background: transparent !important;
    border: 0 !important;
    box-shadow: none !important;
  }

  .lesson-studio-shell .course-hero > div:first-child {
    grid-column: 1 !important;
    grid-row: 2 !important;
    min-width: 0 !important;
  }

  .lesson-studio-shell .course-hero .top-focus {
    grid-column: 2 !important;
    grid-row: 2 !important;
  }

  .lesson-studio-shell .catalog-button strong {
    display: none !important;
  }

  .lesson-studio-shell .catalog-button span {
    white-space: nowrap !important;
  }
}

/* Step evidence polish 2026-07-20: make progress feedback visible without adding a new panel. */
@media (min-width: 1181px) {
  .lesson-stepper {
    gap: 9px !important;
    background:
      linear-gradient(180deg, rgba(255, 255, 255, 0.88), rgba(246, 251, 255, 0.78)) !important;
  }

  .lesson-stepper a {
    position: relative !important;
    min-height: 58px !important;
    grid-template-columns: 30px minmax(0, 1fr) !important;
    grid-template-rows: auto auto !important;
    column-gap: 8px !important;
    row-gap: 2px !important;
    align-content: center !important;
    padding: 8px 8px !important;
    border-radius: 14px !important;
  }

  .lesson-stepper b {
    grid-row: 1 / span 2 !important;
    width: 28px !important;
    height: 28px !important;
    align-self: center !important;
    font-size: 13px !important;
  }

  .lesson-stepper span {
    min-width: 0 !important;
    color: #17384a !important;
    font-size: 12px !important;
    line-height: 1.1 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-stepper small {
    min-width: 0 !important;
    color: #6a7b8f !important;
    font-size: 9px !important;
    line-height: 1.1 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-stepper em {
    position: absolute !important;
    right: 7px !important;
    bottom: 6px !important;
    top: auto !important;
    max-width: 52px !important;
    min-height: 16px !important;
    display: inline-grid !important;
    place-items: center !important;
    border-radius: 999px !important;
    padding: 2px 6px !important;
    background: rgba(86, 108, 128, 0.08) !important;
    color: #64758a !important;
    font-size: 8px !important;
    font-style: normal !important;
    font-weight: 900 !important;
    line-height: 1 !important;
    white-space: nowrap !important;
  }

  .lesson-stepper a.is-active,
  .lesson-stepper a[aria-current="step"] {
    border-color: rgba(31, 111, 229, 0.28) !important;
    background:
      radial-gradient(circle at 12% 0%, rgba(255, 255, 255, 0.98), transparent 34%),
      linear-gradient(180deg, #f1f7ff, #e7f1ff) !important;
    box-shadow: 0 12px 24px rgba(31, 111, 229, 0.12) !important;
  }

  .lesson-stepper a.is-active em,
  .lesson-stepper a[aria-current="step"] em {
    background: #1f6fe5 !important;
    color: #ffffff !important;
  }

  .lesson-stepper a.is-done {
    border-color: rgba(42, 166, 120, 0.24) !important;
    background:
      radial-gradient(circle at 10% 0%, rgba(255, 255, 255, 0.92), transparent 36%),
      linear-gradient(180deg, #f2fbf7, #e6f7ef) !important;
  }

  .lesson-stepper a.is-done b {
    background: linear-gradient(145deg, #2aa678, #287b73) !important;
    color: #ffffff !important;
  }

  .lesson-stepper a.is-done em {
    background: rgba(42, 166, 120, 0.14) !important;
    color: #287b73 !important;
  }

  .lesson-stepper a.is-upcoming {
    opacity: 0.82 !important;
  }
}

@media (max-width: 1180px) {
  .lesson-stepper em {
    display: inline-grid !important;
    place-items: center !important;
    border-radius: 999px !important;
    padding: 2px 6px !important;
    background: rgba(86, 108, 128, 0.08) !important;
    color: #64758a !important;
    font-size: 10px !important;
    font-style: normal !important;
    font-weight: 900 !important;
  }

  .lesson-stepper a.is-active em,
  .lesson-stepper a[aria-current="step"] em {
    background: rgba(31, 111, 229, 0.12) !important;
    color: #1f6fe5 !important;
  }

  .lesson-stepper a.is-done em {
    background: rgba(42, 166, 120, 0.14) !important;
    color: #287b73 !important;
  }
}

/* Practice card fit 2026-07-20: show the real transfer questions and all choices before feedback. */
@media (min-width: 1181px) {
  .lesson-practice .practice-list {
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 10px !important;
  }

  .lesson-practice .practice-card {
    display: grid !important;
    grid-template-rows: 22px minmax(0, 42px) 58px auto !important;
    gap: 5px !important;
    min-height: 126px !important;
    max-height: 126px !important;
    padding: 10px !important;
    overflow: hidden !important;
  }

  .lesson-practice .practice-card-head {
    min-height: 22px !important;
    gap: 6px !important;
  }

  .lesson-practice .practice-card-head span,
  .lesson-practice .practice-card-head em,
  .lesson-practice .practice-question small {
    min-height: 20px !important;
    padding: 0 7px !important;
    font-size: 10px !important;
  }

  .lesson-practice .practice-card-head em {
    max-width: 92px !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-practice .practice-question {
    gap: 3px !important;
    min-height: 0 !important;
    overflow: hidden !important;
  }

  .lesson-practice .practice-question strong {
    font-size: 13px !important;
    line-height: 1.18 !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
  }

  .lesson-practice .practice-question span {
    display: none !important;
  }

  .lesson-practice .practice-question small {
    width: fit-content !important;
    max-width: 100% !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-practice .answer-options,
  .lesson-practice .practice-card .answer-options {
    display: grid !important;
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 6px !important;
    margin: 0 !important;
    min-height: 0 !important;
  }

  .lesson-practice .answer-options button,
  .lesson-studio .lesson-practice .answer-options button {
    min-width: 0 !important;
    min-height: 30px !important;
    max-height: 30px !important;
    padding: 4px 6px !important;
    border-radius: 10px !important;
    font-size: 11px !important;
    line-height: 1.05 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-practice .practice-diagnosis {
    display: none !important;
  }

  .lesson-practice .practice-diagnosis.right,
  .lesson-practice .practice-diagnosis.wrong {
    display: grid !important;
    grid-template-columns: auto minmax(0, 1fr) !important;
    min-height: 34px !important;
    max-height: 34px !important;
    gap: 6px !important;
    padding: 6px 8px !important;
    overflow: hidden !important;
  }

  .lesson-practice .practice-diagnosis.right span,
  .lesson-practice .practice-diagnosis.wrong span {
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-practice .practice-diagnosis.right a,
  .lesson-practice .practice-diagnosis.wrong a {
    display: none !important;
  }
}

@media (max-width: 1180px) {
  .lesson-practice .practice-diagnosis:not(.right):not(.wrong) {
    display: none !important;
  }
}

/* Practice card readable correction 2026-07-20: the choices must be visible, not merely pass layout math. */
@media (min-width: 1181px) {
  .lesson-studio {
    grid-template-rows: 478px 210px auto !important;
  }

  .lesson-practice {
    min-height: 210px !important;
    max-height: 210px !important;
    grid-template-columns: 180px minmax(0, 1fr) !important;
  }

  .lesson-practice .practice-card {
    grid-template-rows: 22px minmax(0, 54px) 44px auto !important;
    min-height: 162px !important;
    max-height: 162px !important;
    padding: 10px !important;
  }

  .lesson-practice .practice-question strong {
    font-size: 13px !important;
    line-height: 1.22 !important;
  }

  .lesson-practice .practice-question small {
    display: inline-flex !important;
  }

  .lesson-practice .answer-options,
  .lesson-practice .practice-card .answer-options {
    align-content: start !important;
  }

  .lesson-practice .answer-options button,
  .lesson-studio .lesson-practice .answer-options button {
    min-height: 36px !important;
    max-height: 36px !important;
    font-size: 12px !important;
  }

  .lesson-mistake-panel .mistake-card,
  .lesson-mistake-panel .complete-button {
    min-height: 58px !important;
  }
}

/* Course QA readability pass 2026-07-20: questions and long answer choices must be visible. */
@media (min-width: 1181px) {
  .lesson-practice .practice-card {
    grid-template-rows: 22px 38px 48px auto !important;
    gap: 6px !important;
  }

  .lesson-practice .practice-question {
    display: block !important;
    min-height: 38px !important;
    max-height: 38px !important;
    overflow: hidden !important;
  }

  .lesson-practice .practice-question strong {
    display: -webkit-box !important;
    min-height: 32px !important;
    max-height: 36px !important;
    font-size: 13px !important;
    line-height: 1.28 !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
    white-space: normal !important;
  }

  .lesson-practice .practice-question span,
  .lesson-practice .practice-question small {
    display: none !important;
  }

  .lesson-practice .answer-options,
  .lesson-practice .practice-card .answer-options {
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    align-items: stretch !important;
    gap: 6px !important;
    min-height: 48px !important;
  }

  .lesson-practice .answer-options button,
  .lesson-studio .lesson-practice .answer-options button {
    min-height: 44px !important;
    max-height: 44px !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    padding: 4px 6px !important;
    font-size: 10px !important;
    line-height: 1.2 !important;
    text-align: center !important;
    white-space: normal !important;
    overflow: hidden !important;
    overflow-wrap: anywhere !important;
    word-break: normal !important;
  }

  .lesson-practice .practice-diagnosis.right,
  .lesson-practice .practice-diagnosis.wrong {
    min-height: 36px !important;
    max-height: 36px !important;
  }

  .lesson-mistake-panel .mistake-card {
    min-height: 96px !important;
    max-height: 96px !important;
    overflow: hidden !important;
  }

  .lesson-mistake-panel .mistake-card p {
    display: -webkit-box !important;
    min-height: 36px !important;
    max-height: 38px !important;
    line-height: 1.34 !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
  }

  .lesson-mistake-panel .complete-button {
    min-height: 96px !important;
    max-height: 96px !important;
  }
}

@media (max-width: 1180px) {
  .lesson-practice .practice-question strong {
    white-space: normal !important;
    overflow-wrap: anywhere !important;
  }

  .lesson-practice .answer-options button,
  .lesson-studio .lesson-practice .answer-options button {
    line-height: 1.3 !important;
    white-space: normal !important;
    overflow-wrap: anywhere !important;
  }

  .lesson-mistake-panel .mistake-card p {
    line-height: 1.4 !important;
    overflow-wrap: anywhere !important;
  }
}

/* Course mobile focus 2026-07-20: make the first viewport about one action and one model. */
@media (max-width: 760px) {
  .lesson-studio-shell {
    width: min(100% - 16px, 430px) !important;
    padding-top: 8px !important;
  }

  .lesson-studio-shell .course-hero {
    min-height: 108px !important;
    margin-bottom: 8px !important;
    border-radius: 20px !important;
    padding: 8px 12px 10px !important;
  }

  .lesson-studio-shell .course-nav {
    min-height: 44px !important;
    margin: 0 !important;
  }

  .lesson-studio-shell .course-hero h1 {
    font-size: 24px !important;
    line-height: 1.08 !important;
  }

  .lesson-studio-shell .course-hero .top-focus span:not(:first-child) {
    display: none !important;
  }

  .lesson-action-board {
    display: grid !important;
    grid-template-columns: 1fr auto !important;
    min-height: 54px !important;
    margin-bottom: 8px !important;
    gap: 8px !important;
  }

  .lesson-action-board article:not(.lesson-action-primary) {
    display: none !important;
  }

  .lesson-action-primary {
    grid-template-columns: minmax(0, 1fr) auto !important;
    align-items: center !important;
    min-height: 54px !important;
    border-radius: 14px !important;
    padding: 8px 10px !important;
  }

  .lesson-action-primary span,
  .lesson-action-primary p {
    display: none !important;
  }

  .lesson-action-primary strong {
    font-size: 15px !important;
    line-height: 1.12 !important;
  }

  .lesson-action-primary a {
    min-height: 34px !important;
    border-radius: 999px !important;
    padding: 0 13px !important;
    font-size: 12px !important;
  }

  .lesson-stepper {
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 8px !important;
    margin-bottom: 8px !important;
    padding: 8px !important;
    border-radius: 16px !important;
  }

  .lesson-stepper a {
    min-height: 54px !important;
    grid-template-columns: 24px minmax(0, 1fr) !important;
    gap: 5px !important;
    padding: 7px !important;
    border-radius: 12px !important;
  }

  .lesson-stepper b {
    width: 24px !important;
    height: 24px !important;
    font-size: 12px !important;
  }

  .lesson-stepper span {
    font-size: 11px !important;
    line-height: 1.1 !important;
  }

  .lesson-stepper small,
  .lesson-stepper em {
    display: none !important;
  }

  .lesson-main {
    gap: 8px !important;
  }

  .lesson-main .course-prompt {
    min-height: 74px !important;
    border-radius: 18px !important;
    padding: 10px 12px !important;
  }

  .lesson-main .course-prompt h2 {
    font-size: 17px !important;
    line-height: 1.18 !important;
  }

  .lesson-main .course-prompt .choice-row {
    grid-template-columns: 1fr !important;
    gap: 6px !important;
  }

  .lesson-main .course-prompt .choice-row button:not(:first-child) {
    display: none !important;
  }

  .lesson-studio .model-card {
    display: grid !important;
    grid-template-rows: 68px 38px 0 minmax(0, 358px) 40px !important;
    min-height: 512px !important;
    max-height: 512px !important;
    border-radius: 20px !important;
    overflow: hidden !important;
  }

  .lesson-studio .model-head {
    min-height: 56px !important;
    margin: 10px 10px 0 !important;
    padding: 8px 10px !important;
    border-radius: 14px !important;
  }

  .lesson-studio .model-head h2 {
    font-size: 17px !important;
    line-height: 1.16 !important;
    -webkit-line-clamp: 2 !important;
  }

  .lesson-studio .model-head .ghost-button {
    min-width: 60px !important;
    min-height: 34px !important;
    border-radius: 10px !important;
  }

  .lesson-studio .formula-strip {
    min-height: 38px !important;
    max-height: 38px !important;
    margin: 0 10px !important;
    overflow: hidden !important;
  }

  .lesson-studio .formula-pill {
    min-height: 28px !important;
    padding: 5px 10px !important;
    font-size: 11px !important;
  }

  .lesson-studio .model-feedback {
    display: none !important;
  }

  .lesson-studio .visual-stage {
    min-height: 358px !important;
    height: 358px !important;
    margin: 0 10px !important;
    padding: 8px !important;
    overflow: hidden !important;
    border-radius: 16px !important;
  }

  .lesson-studio .course-controls {
    min-height: 34px !important;
    margin: 0 10px 8px !important;
  }

  .lesson-studio .course-controls button {
    min-height: 32px !important;
    border-radius: 10px !important;
    font-size: 11px !important;
  }

  .lesson-studio .visual-stage .equation-responsive-board {
    display: grid !important;
    grid-template-rows: 36px minmax(0, 304px) !important;
    gap: 6px !important;
    height: 100% !important;
    max-height: 342px !important;
    overflow: hidden !important;
    border: 0 !important;
    background: transparent !important;
    padding: 0 !important;
  }

  .lesson-studio .visual-stage .balance-step-panel {
    grid-row: 1 !important;
    min-height: 36px !important;
    margin: 0 !important;
    padding: 0 !important;
    border: 0 !important;
    background: transparent !important;
    box-shadow: none !important;
  }

  .lesson-studio .visual-stage .balance-step-panel button {
    min-height: 34px !important;
    border-radius: 999px !important;
    font-size: 12px !important;
  }

  .lesson-studio .visual-stage .balance-step-panel span {
    display: none !important;
  }

  .mobile-equation-balance {
    grid-row: 2 !important;
    grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
    gap: 8px !important;
    align-content: start !important;
    height: 304px !important;
    overflow: hidden !important;
  }

  .mobile-equation-title {
    font-size: 22px !important;
    line-height: 1 !important;
    margin: 0 !important;
  }

  .mobile-balance-beam {
    height: 8px !important;
    margin: 0 !important;
  }

  .mobile-pan {
    gap: 5px !important;
    min-height: 142px !important;
    border-radius: 12px !important;
    padding: 8px !important;
  }

  .mobile-pan > span,
  .mobile-pan > em {
    font-size: 12px !important;
  }

  .mobile-drag-zone {
    min-height: 56px !important;
    gap: 5px !important;
    border-radius: 10px !important;
  }

  .result-zone {
    min-height: 70px !important;
    font-size: 26px !important;
  }

  .mini-x,
  .mini-one,
  .mini-neg,
  .mini-zero {
    min-width: 30px !important;
    min-height: 28px !important;
    border-radius: 8px !important;
    font-size: 15px !important;
  }

  .mobile-equation-balance p {
    margin: 0 !important;
    font-size: 12px !important;
    line-height: 1.2 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }
}

/* Course mobile focus2 override 2026-07-20: one action, one model, visible feedback. */
@media (max-width: 760px) {
  .lesson-dashboard-strip,
  .lesson-journey,
  .lesson-proofbar,
  .lesson-action-board {
    display: none !important;
  }

  .lesson-stepper {
    display: flex !important;
    align-items: center !important;
    min-height: 38px !important;
    margin: 0 0 8px !important;
    padding: 5px !important;
    border-radius: 999px !important;
    overflow: hidden !important;
    background: rgba(255, 255, 255, .66) !important;
    border-color: rgba(120, 148, 156, .16) !important;
  }

  .lesson-stepper a {
    display: none !important;
  }

  .lesson-stepper a.is-active,
  .lesson-stepper a[aria-current="step"] {
    display: grid !important;
    grid-template-columns: 28px minmax(0, 1fr) auto !important;
    width: 100% !important;
    min-height: 28px !important;
    padding: 3px 12px 3px 4px !important;
    border-radius: 999px !important;
    background: #ffffff !important;
  }

  .lesson-stepper a.is-active::after,
  .lesson-stepper a[aria-current="step"]::after {
    content: "第 2 / 6 步";
    align-self: center;
    color: rgba(37, 62, 70, .58);
    font-size: 11px;
    font-weight: 800;
  }

  .lesson-main {
    gap: 8px !important;
  }

  .lesson-main .course-prompt {
    min-height: 78px !important;
    padding: 10px 12px !important;
    border-radius: 18px !important;
    background: rgba(255, 255, 255, .78) !important;
  }

  .lesson-main .course-prompt .eyebrow,
  .lesson-main .course-prompt .choice-row,
  .lesson-main .course-prompt .feedback {
    display: none !important;
  }

  .lesson-main .course-prompt h2 {
    font-size: 18px !important;
    line-height: 1.2 !important;
    letter-spacing: 0 !important;
    display: block !important;
    -webkit-line-clamp: unset !important;
    overflow: visible !important;
  }

  .lesson-studio .model-card {
    grid-template-rows: 56px 32px 42px minmax(0, 332px) 0 !important;
    min-height: 486px !important;
    max-height: 486px !important;
    border-radius: 20px !important;
  }

  .lesson-studio .model-head {
    grid-template-columns: minmax(0, 1fr) auto !important;
    min-height: 46px !important;
    margin: 8px 8px 0 !important;
    padding: 7px 9px !important;
    border-radius: 14px !important;
  }

  .lesson-studio .model-head .eyebrow {
    display: none !important;
  }

  .lesson-studio .model-head h2 {
    font-size: 15px !important;
    line-height: 1.16 !important;
    -webkit-line-clamp: 2 !important;
  }

  .lesson-studio .model-head .ghost-button {
    min-width: 46px !important;
    min-height: 32px !important;
    padding: 0 9px !important;
    font-size: 11px !important;
    opacity: .78 !important;
  }

  .lesson-studio .formula-strip {
    min-height: 32px !important;
    max-height: 32px !important;
    margin: 0 8px !important;
  }

  .lesson-studio .formula-pill {
    min-height: 26px !important;
    padding: 4px 8px !important;
    font-size: 10px !important;
  }

  .lesson-studio .model-feedback {
    display: block !important;
    min-height: 38px !important;
    max-height: 38px !important;
    margin: 0 8px !important;
    padding: 6px 10px !important;
    border-radius: 14px !important;
    font-size: 12px !important;
    line-height: 1.2 !important;
    overflow: hidden !important;
    color: #17463f !important;
    background: rgba(229, 247, 239, .92) !important;
    border: 1px solid rgba(74, 154, 130, .26) !important;
  }

  .lesson-studio .visual-stage {
    min-height: 332px !important;
    height: 332px !important;
    margin: 0 8px !important;
    padding: 7px !important;
    border-radius: 16px !important;
  }

  .lesson-studio .course-controls {
    min-height: 0 !important;
    max-height: 0 !important;
    margin: 0 !important;
    padding: 0 !important;
    overflow: hidden !important;
  }

  .lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: 40px minmax(0, 278px) !important;
    gap: 7px !important;
    max-height: 318px !important;
  }

  .lesson-studio .visual-stage .balance-step-panel {
    min-height: 40px !important;
  }

  .lesson-studio .visual-stage .balance-step-panel button {
    width: 100% !important;
    min-height: 40px !important;
    border-radius: 999px !important;
    font-size: 14px !important;
    box-shadow: 0 10px 22px rgba(30, 115, 92, .16) !important;
  }

  .lesson-studio .visual-stage .balance-step-panel span {
    display: none !important;
  }

  .mobile-equation-balance {
    height: 278px !important;
    grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
    gap: 7px !important;
    overflow: hidden !important;
  }

  .mobile-equation-title {
    grid-column: 1 / -1 !important;
    font-size: 21px !important;
  }

  .mobile-balance-beam {
    grid-column: 1 / -1 !important;
    height: 7px !important;
  }

  .mobile-pan {
    min-height: 124px !important;
    padding: 7px !important;
    gap: 5px !important;
  }

  .mobile-drag-zone {
    min-height: 44px !important;
    gap: 4px !important;
  }

  .result-zone {
    min-height: 64px !important;
    font-size: 25px !important;
  }

  .mini-x,
  .mini-one,
  .mini-neg,
  .mini-zero {
    min-width: 27px !important;
    min-height: 25px !important;
    font-size: 13px !important;
  }

  .mobile-equation-balance p {
    grid-column: 1 / -1 !important;
    min-height: 31px !important;
    margin: 0 !important;
    padding: 4px 8px !important;
    border-radius: 12px !important;
    background: rgba(255, 255, 255, .7) !important;
    font-size: 12px !important;
    line-height: 1.18 !important;
    white-space: normal !important;
    overflow: hidden !important;
    text-overflow: clip !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
  }
}

/* Course mobile focus2 final gate: keep the override last. */
@media (max-width: 760px) {
  .lesson-stepper a.is-active::after,
  .lesson-stepper a[aria-current="step"]::after {
    content: "2 / 6";
  }

  .lesson-stepper a.is-active,
  .lesson-stepper a[aria-current="step"] {
    min-height: 36px !important;
    padding: 8px 12px 8px 8px !important;
  }

  .lesson-main .course-prompt {
    order: 1 !important;
    grid-row: 1 !important;
  }

  .lesson-studio .model-card {
    order: 2 !important;
    grid-row: 2 !important;
    grid-template-rows: 64px 42px 50px minmax(0, 306px) 0 !important;
    min-height: 486px !important;
    max-height: 486px !important;
  }

  .lesson-studio .model-head {
    grid-row: 1 !important;
    grid-template-columns: minmax(0, 1fr) !important;
    min-height: 56px !important;
  }

  .lesson-studio .model-head .ghost-button {
    display: none !important;
  }

  .lesson-studio .formula-strip {
    grid-row: 2 !important;
    min-height: 42px !important;
    max-height: 42px !important;
    align-items: center !important;
    flex-wrap: nowrap !important;
    white-space: nowrap !important;
    overflow-x: auto !important;
    overflow-y: hidden !important;
  }

  .lesson-studio .formula-pill {
    min-height: 34px !important;
    padding: 8px 10px !important;
    margin-top: 0 !important;
    margin-bottom: 0 !important;
    flex: 0 0 auto !important;
    white-space: nowrap !important;
  }

  .lesson-studio .model-feedback {
    grid-row: 3 !important;
    min-height: 46px !important;
    max-height: 46px !important;
    white-space: normal !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
  }

  .lesson-studio .visual-stage {
    grid-row: 4 !important;
    min-height: 306px !important;
    height: 306px !important;
    overflow: auto !important;
    scrollbar-width: thin !important;
  }

  .lesson-studio .course-controls {
    grid-row: 5 !important;
    display: none !important;
  }

  .lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: 40px minmax(0, 252px) !important;
    max-height: 292px !important;
  }

  .mobile-equation-balance {
    height: 252px !important;
  }

  .lesson-studio .visual-stage .model-caption {
    display: none !important;
  }

  .lesson-studio .visual-stage.course-stage.is-direct-stage {
    display: grid !important;
    align-items: stretch !important;
    justify-items: stretch !important;
  }

  .lesson-studio .visual-stage .expression-lab,
  .lesson-studio .visual-stage .expression-main-canvas {
    position: static !important;
    transform: none !important;
    height: 100% !important;
    min-height: 0 !important;
    max-height: 100% !important;
    overflow: hidden !important;
  }

  .lesson-studio .visual-stage .expression-workbench {
    height: 100% !important;
    min-height: 0 !important;
    grid-template-rows: auto auto minmax(0, 1fr) !important;
    gap: 6px !important;
    padding: 8px !important;
    overflow: hidden !important;
  }

  .lesson-studio .visual-stage .expression-head,
  .lesson-studio .visual-stage .expression-task,
  .lesson-studio .visual-stage .expression-invariant {
    display: none !important;
  }

  .lesson-studio .visual-stage .expression-word-card {
    display: grid !important;
    grid-template-columns: 1fr !important;
    gap: 5px !important;
    padding: 6px !important;
  }

  .lesson-studio .visual-stage .expression-word-card span,
  .lesson-studio .visual-stage .expression-action-chip,
  .lesson-studio .visual-stage .expression-word-card em {
    min-height: 36px !important;
    font-size: 12px !important;
    padding: 8px !important;
  }

  .lesson-studio .visual-stage .expression-reading {
    display: none !important;
  }

  .lesson-studio .visual-stage .expression-scene {
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) 92px !important;
    gap: 6px !important;
    min-height: 0 !important;
    height: 128px !important;
    max-height: 128px !important;
    overflow: hidden !important;
    padding: 6px !important;
  }

  .lesson-studio .visual-stage .expression-dropzone,
  .lesson-studio .visual-stage .expression-palette {
    min-height: 0 !important;
    height: 100% !important;
    max-height: 116px !important;
    overflow: hidden !important;
    padding: 6px !important;
  }

  .lesson-studio .visual-stage .expression-dropzone {
    display: grid !important;
    grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
    align-content: start !important;
    gap: 4px !important;
  }

  .lesson-studio .visual-stage .palette-label,
  .lesson-studio .visual-stage .palette-note,
  .lesson-studio .visual-stage .dropzone-label {
    display: none !important;
  }

  .lesson-studio .visual-stage .palette-tiles {
    display: grid !important;
    grid-template-columns: 1fr !important;
    gap: 4px !important;
  }

  .lesson-studio .visual-stage .expression-tile {
    min-width: 0 !important;
    width: 100% !important;
    height: 28px !important;
    min-height: 28px !important;
    font-size: 12px !important;
    padding: 4px !important;
  }

  .lesson-studio .visual-stage .expression-palette .expression-tile {
    height: 24px !important;
    min-height: 24px !important;
  }
}

/* Course calm4: practice evidence must be readable, especially after adding transfer tasks. */
@media (min-width: 1181px) {
  .lesson-studio {
    grid-template-rows: 478px auto auto !important;
  }

  .lesson-practice {
    min-height: 246px !important;
    height: auto !important;
    max-height: none !important;
    grid-template-columns: 168px minmax(0, 1fr) !important;
    align-items: stretch !important;
    overflow: visible !important;
  }

  .lesson-practice .practice-list {
    display: grid !important;
    grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
    gap: 10px !important;
    min-height: 0 !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  .lesson-practice .practice-card {
    display: grid !important;
    grid-template-rows: auto minmax(62px, auto) auto auto !important;
    gap: 8px !important;
    min-height: 190px !important;
    height: auto !important;
    max-height: none !important;
    padding: 12px !important;
    overflow: visible !important;
  }

  .lesson-practice .practice-card-head {
    min-height: 24px !important;
  }

  .lesson-practice .practice-question {
    display: grid !important;
    gap: 4px !important;
    min-height: 62px !important;
    max-height: none !important;
    overflow: visible !important;
  }

  .lesson-practice .practice-question strong {
    display: block !important;
    min-height: 0 !important;
    max-height: none !important;
    font-size: 13px !important;
    line-height: 1.28 !important;
    overflow: visible !important;
    white-space: normal !important;
  }

  .lesson-practice .practice-question span {
    display: -webkit-box !important;
    color: #5f7188 !important;
    font-size: 11px !important;
    line-height: 1.22 !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
  }

  .lesson-practice .practice-question small {
    display: inline-flex !important;
    width: fit-content !important;
    color: #26766c !important;
    font-size: 10px !important;
    font-weight: 900 !important;
  }

  .lesson-practice .answer-options,
  .lesson-practice .practice-card .answer-options {
    display: grid !important;
    grid-template-columns: 1fr !important;
    gap: 6px !important;
    min-height: 0 !important;
    height: auto !important;
  }

  .lesson-practice .answer-options button,
  .lesson-studio .lesson-practice .answer-options button {
    min-height: 32px !important;
    max-height: none !important;
    font-size: 12px !important;
    line-height: 1.15 !important;
    white-space: normal !important;
    overflow: visible !important;
  }

  .lesson-practice .practice-diagnosis:not(.right):not(.wrong) {
    display: none !important;
  }
}

@media (min-width: 1181px) and (max-width: 1380px) {
  .lesson-practice .practice-list {
    grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
  }
}

/* Course practice final card pass 2026-07-20: questions must read as solvable tasks, not thin controls. */
@media (min-width: 1181px) {
  .lesson-studio {
    grid-template-rows: 488px 184px auto !important;
  }

  .lesson-studio .model-card {
    max-height: 488px !important;
  }

  .lesson-studio .visual-stage {
    max-height: 326px !important;
  }

  .lesson-practice {
    min-height: 184px !important;
    max-height: 184px !important;
    grid-template-columns: 178px minmax(0, 1fr) !important;
    align-items: stretch !important;
    gap: 12px !important;
    padding: 14px !important;
    background:
      radial-gradient(circle at 12% 0%, rgba(133, 199, 197, 0.08), transparent 34%),
      rgba(255, 255, 255, 0.76) !important;
  }

  .lesson-practice > div:first-child {
    display: grid !important;
    align-content: center !important;
    gap: 8px !important;
    min-width: 0 !important;
    border-right: 1px solid rgba(55, 92, 111, 0.08) !important;
    padding-right: 12px !important;
  }

  .lesson-practice .eyebrow {
    margin: 0 !important;
    color: #1f6fe5 !important;
    font-size: 12px !important;
    font-weight: 900 !important;
  }

  .lesson-practice h2 {
    max-width: 150px !important;
    color: #173047 !important;
    font-size: 18px !important;
    line-height: 1.16 !important;
  }

  .lesson-practice .practice-list {
    display: grid !important;
    grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
    gap: 10px !important;
    align-items: stretch !important;
  }

  .lesson-practice .practice-card {
    display: grid !important;
    grid-template-rows: 20px 42px minmax(0, 70px) 0 !important;
    gap: 5px !important;
    min-height: 156px !important;
    max-height: 156px !important;
    border: 1px solid rgba(55, 92, 111, 0.1) !important;
    border-radius: 16px !important;
    background:
      linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(247, 251, 249, 0.86)) !important;
    box-shadow: 0 12px 26px rgba(30, 60, 82, 0.045) !important;
    padding: 10px !important;
    overflow: visible !important;
  }

  .lesson-practice .practice-card-head {
    min-height: 20px !important;
    gap: 6px !important;
  }

  .lesson-practice .practice-card-head span,
  .lesson-practice .practice-card-head em {
    display: inline-flex !important;
    align-items: center !important;
    min-height: 19px !important;
    border-radius: 999px !important;
    padding: 0 8px !important;
    font-size: 10px !important;
    line-height: 1 !important;
    white-space: nowrap !important;
  }

  .lesson-practice .practice-card-head span {
    background: rgba(31, 111, 229, 0.1) !important;
    color: #1f6fe5 !important;
  }

  .lesson-practice .practice-card-head em {
    max-width: 98px !important;
    background: rgba(42, 166, 120, 0.1) !important;
    color: #287b73 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  .lesson-practice .practice-question {
    display: grid !important;
    gap: 4px !important;
    min-height: 42px !important;
    max-height: 42px !important;
    overflow: hidden !important;
  }

  .lesson-practice .practice-question strong {
    display: -webkit-box !important;
    min-height: 34px !important;
    max-height: 36px !important;
    color: #173047 !important;
    font-size: 13px !important;
    font-weight: 900 !important;
    line-height: 1.25 !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
    white-space: normal !important;
  }

  .lesson-practice .practice-question span {
    display: none !important;
  }

  .lesson-practice .practice-question small {
    display: none !important;
    width: fit-content !important;
    max-width: 100% !important;
    min-height: 18px !important;
    align-items: center !important;
    border-radius: 999px !important;
    background: rgba(95, 117, 132, 0.08) !important;
    color: #627189 !important;
    padding: 0 7px !important;
    font-size: 10px !important;
    font-weight: 850 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-practice .answer-options,
  .lesson-practice .practice-card .answer-options {
    display: grid !important;
    grid-template-columns: 1fr !important;
    gap: 6px !important;
    min-height: 70px !important;
    align-items: stretch !important;
  }

  .lesson-practice .answer-options button,
  .lesson-studio .lesson-practice .answer-options button {
    display: grid !important;
    grid-template-columns: 18px minmax(0, 1fr) !important;
    align-items: center !important;
    justify-items: start !important;
    gap: 6px !important;
    min-width: 0 !important;
    min-height: 22px !important;
    max-height: 22px !important;
    border: 1px solid rgba(31, 111, 229, 0.14) !important;
    border-radius: 10px !important;
    background: rgba(255, 255, 255, 0.92) !important;
    color: #16406f !important;
    padding: 3px 8px !important;
    font-size: 12px !important;
    font-weight: 900 !important;
    line-height: 1.12 !important;
    text-align: left !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  .lesson-practice .answer-options button::before,
  .lesson-studio .lesson-practice .answer-options button::before {
    display: grid !important;
    width: 18px !important;
    height: 18px !important;
    place-items: center !important;
    border-radius: 50% !important;
    background: rgba(31, 111, 229, 0.1) !important;
    color: #1f6fe5 !important;
    font-size: 10px !important;
    font-weight: 950 !important;
  }

  .lesson-practice .answer-options button:nth-child(1)::before { content: "A" !important; }
  .lesson-practice .answer-options button:nth-child(2)::before { content: "B" !important; }
  .lesson-practice .answer-options button:nth-child(3)::before { content: "C" !important; }
  .lesson-practice .answer-options button:nth-child(4)::before { content: "D" !important; }

  .lesson-practice .answer-options button:hover,
  .lesson-studio .lesson-practice .answer-options button:hover {
    border-color: rgba(31, 111, 229, 0.34) !important;
    background: rgba(237, 246, 255, 0.96) !important;
  }

  .lesson-practice .answer-options button.is-right {
    border-color: rgba(42, 166, 120, 0.42) !important;
    background: rgba(232, 247, 239, 0.96) !important;
    color: #287b73 !important;
  }

  .lesson-practice .answer-options button.is-wrong {
    border-color: rgba(224, 101, 111, 0.36) !important;
    background: rgba(255, 239, 240, 0.95) !important;
    color: #a83f4a !important;
  }

  .lesson-practice .practice-diagnosis {
    display: none !important;
    grid-template-columns: auto minmax(0, 1fr) !important;
    align-items: center !important;
    gap: 6px !important;
    min-height: 36px !important;
    max-height: 36px !important;
    margin: 0 !important;
    border-radius: 12px !important;
    background: rgba(247, 251, 255, 0.82) !important;
    padding: 6px 8px !important;
    overflow: hidden !important;
  }

  .lesson-practice .practice-diagnosis b {
    color: #617386 !important;
    font-size: 11px !important;
    white-space: nowrap !important;
  }

  .lesson-practice .practice-diagnosis span {
    color: #627189 !important;
    font-size: 11px !important;
    line-height: 1.2 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
  }

  .lesson-practice .practice-diagnosis a {
    display: none !important;
  }

  .lesson-practice .practice-diagnosis.right,
  .lesson-practice .practice-diagnosis.wrong {
    display: grid !important;
  }

  .lesson-practice .practice-diagnosis.right {
    background: rgba(232, 247, 239, 0.92) !important;
  }

  .lesson-practice .practice-diagnosis.wrong {
    background: rgba(255, 239, 240, 0.92) !important;
  }
}

/* Specificity lock: override earlier course-calm layout rules that also use !important. */
@media (min-width: 1181px) {
  body .learning-flow.course-flow.lesson-studio {
    grid-template-rows: 562px 188px 44px !important;
  }

  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    min-height: 188px !important;
    height: 188px !important;
    max-height: 188px !important;
    grid-template-columns: 178px minmax(0, 1fr) !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-practice .practice-list,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-list {
    grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
    grid-template-rows: 160px !important;
    align-items: stretch !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-practice .practice-card,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card {
    min-height: 160px !important;
    height: 160px !important;
    max-height: 160px !important;
    grid-template-rows: 20px 36px 66px 0 !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-practice .practice-diagnosis:not(.right):not(.wrong),
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-diagnosis:not(.right):not(.wrong) {
    display: none !important;
  }

  body .lesson-studio .lesson-practice .answer-options,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options {
    grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
    gap: 6px !important;
    min-height: 66px !important;
  }

  body .lesson-studio .lesson-practice .answer-options button,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options button {
    min-height: 30px !important;
    max-height: 30px !important;
    font-size: 11px !important;
  }
}

/* Course calm4: step-lock equation answers until the balance model has been operated. */
.equation-responsive-board .balance-handle {
  transition: opacity 160ms ease, filter 160ms ease;
}

.equation-responsive-board.is-stage-constant .balance-x-group,
.equation-responsive-board.is-stage-constant .balance-result-group,
.equation-responsive-board.is-stage-split .balance-unit-group,
.equation-responsive-board.is-stage-split .balance-result-group {
  opacity: 0.66;
}

.equation-responsive-board .balance-handle.is-current-target {
  opacity: 1;
  filter: drop-shadow(0 14px 22px rgba(31, 111, 229, 0.24));
}

.equation-responsive-board .balance-handle.is-current-target rect[fill="transparent"] {
  stroke-width: 3.5;
  stroke-dasharray: 6 5;
  animation: balanceTargetPulse 1.25s ease-in-out infinite;
}

.balance-equation-flow text {
  letter-spacing: 0;
}

@keyframes balanceTargetPulse {
  0%, 100% {
    stroke-opacity: 0.44;
  }
  50% {
    stroke-opacity: 0.95;
  }
}

/* Course calm6: readable transfer-practice cards, no clipped task wording. */
@media (min-width: 1181px) {
  body .learning-flow.course-flow.lesson-studio {
    grid-template-rows: 472px 218px auto !important;
  }

  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    min-height: 218px !important;
    height: 218px !important;
    max-height: 218px !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    max-height: 472px !important;
  }

  body .lesson-studio .lesson-practice .practice-list,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-list {
    grid-template-columns: repeat(4, minmax(0, 1fr)) !important;
    grid-template-rows: 190px !important;
    gap: 10px !important;
  }

  body .lesson-studio .lesson-practice .practice-card,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card {
    min-height: 190px !important;
    height: 190px !important;
    max-height: 190px !important;
    grid-template-rows: 20px minmax(50px, auto) minmax(76px, auto) 0 !important;
    gap: 7px !important;
  }

  body .lesson-studio .lesson-practice .practice-question,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question {
    min-height: 50px !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-practice .practice-question strong,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question strong {
    display: block !important;
    min-height: 0 !important;
    max-height: none !important;
    overflow: visible !important;
    text-overflow: clip !important;
    -webkit-line-clamp: unset !important;
    line-height: 1.28 !important;
  }

  body .lesson-studio .lesson-practice .answer-options,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options {
    grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
    min-height: 76px !important;
    gap: 7px !important;
  }

  body .lesson-studio .lesson-practice .answer-options button,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options button {
    min-height: 34px !important;
    max-height: none !important;
    white-space: normal !important;
    overflow: visible !important;
    text-overflow: clip !important;
    line-height: 1.18 !important;
  }
}

/* Course calm7: keep the main model and transfer practice in separate rows. */
@media (min-width: 1181px) {
  body .learning-flow.course-flow.lesson-studio,
  body .lesson-studio {
    grid-template-rows: 524px 210px auto !important;
  }

  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main {
    min-height: 524px !important;
    max-height: 524px !important;
    overflow: visible !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    min-height: 410px !important;
    height: 410px !important;
    max-height: 410px !important;
    grid-template-rows: 54px 34px 28px minmax(0, 250px) 32px !important;
    overflow: hidden !important;
  }

  body .lesson-studio .model-head,
  body .learning-flow.course-flow.lesson-studio .model-head {
    min-height: 48px !important;
    margin: 6px 8px 0 !important;
    padding: 7px 10px !important;
  }

  body .lesson-studio .model-head h2,
  body .learning-flow.course-flow.lesson-studio .model-head h2 {
    font-size: 18px !important;
    line-height: 1.12 !important;
  }

  body .lesson-studio .formula-strip,
  body .learning-flow.course-flow.lesson-studio .formula-strip {
    min-height: 34px !important;
    max-height: 34px !important;
    margin: 0 8px !important;
  }

  body .lesson-studio .model-feedback,
  body .learning-flow.course-flow.lesson-studio .model-feedback {
    min-height: 28px !important;
    max-height: 28px !important;
    margin: 0 8px !important;
    overflow: hidden !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    min-height: 250px !important;
    height: 250px !important;
    max-height: 250px !important;
    margin: 0 8px !important;
    padding: 6px !important;
    overflow: hidden !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board,
  body .learning-flow.course-flow.lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: 32px minmax(0, 204px) !important;
    gap: 4px !important;
    max-height: 238px !important;
  }

  body .lesson-studio .visual-stage .desktop-equation-balance,
  body .learning-flow.course-flow.lesson-studio .visual-stage .desktop-equation-balance {
    grid-row: 2 !important;
    align-self: center !important;
    justify-self: center !important;
    position: static !important;
    transform: none !important;
    width: 100% !important;
    max-height: 204px !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel,
  body .learning-flow.course-flow.lesson-studio .visual-stage .balance-step-panel {
    grid-row: 1 !important;
  }

  body .lesson-studio .course-controls,
  body .learning-flow.course-flow.lesson-studio .course-controls {
    min-height: 32px !important;
    max-height: 32px !important;
    margin: 0 8px 6px !important;
  }

  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    position: relative !important;
    z-index: 2 !important;
    min-height: 210px !important;
    height: 210px !important;
    max-height: 210px !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-practice .practice-list,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-list {
    grid-template-rows: 168px !important;
  }

  body .lesson-studio .lesson-practice .practice-card,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card {
    min-height: 168px !important;
    height: 168px !important;
    max-height: 168px !important;
    grid-template-rows: 20px 52px 62px 0 !important;
    gap: 5px !important;
    padding: 10px !important;
  }

  body .lesson-studio .lesson-practice .practice-question,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question {
    min-height: 52px !important;
    height: 52px !important;
    max-height: 52px !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-practice .practice-question strong,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question strong {
    font-size: 12px !important;
    line-height: 1.2 !important;
    max-height: none !important;
    -webkit-line-clamp: unset !important;
  }

  body .lesson-studio .lesson-practice .answer-options,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options {
    min-height: 62px !important;
    gap: 6px !important;
  }

  body .lesson-studio .lesson-practice .answer-options button,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options button {
    min-height: 28px !important;
    font-size: 11px !important;
    line-height: 1.12 !important;
  }
}

/* Course calm8: make transfer practice read as one main task plus variants. */
@media (min-width: 1181px) {
  body .lesson-studio .lesson-practice .practice-list,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-list {
    grid-template-columns: minmax(286px, 1.45fr) repeat(3, minmax(0, 1fr)) !important;
    gap: 9px !important;
  }

  body .lesson-studio .lesson-practice .practice-card,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card {
    border-radius: 15px !important;
    background: rgba(255, 255, 255, 0.82) !important;
    box-shadow: 0 10px 24px rgba(31, 56, 72, 0.038) !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child {
    border-color: rgba(31, 111, 229, 0.16) !important;
    background:
      radial-gradient(circle at 8% 0%, rgba(237, 246, 255, 0.92), transparent 40%),
      linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(247, 252, 251, 0.88)) !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child .practice-card-head span,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .practice-card-head span {
    background: #1f6fe5 !important;
    color: #fff !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child .practice-question strong,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .practice-question strong {
    font-size: 13px !important;
    line-height: 1.2 !important;
  }

  body .lesson-studio .lesson-practice .practice-card:not(:first-child) .practice-card-head em,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:not(:first-child) .practice-card-head em {
    display: none !important;
  }

  body .lesson-studio .lesson-practice .practice-card:not(:first-child) .practice-question strong,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:not(:first-child) .practice-question strong {
    font-size: 11px !important;
    line-height: 1.18 !important;
  }

  body .lesson-studio .lesson-practice .practice-card:not(:first-child) .answer-options button,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:not(:first-child) .answer-options button {
    padding: 2px 6px !important;
  }
}

/* Course calm9: give the core manipulative more visual weight without losing the one-screen cockpit. */
@media (min-width: 1181px) {
  body .learning-flow.course-flow.lesson-studio,
  body .lesson-studio {
    grid-template-rows: 548px 190px auto !important;
  }

  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main {
    min-height: 548px !important;
    max-height: 548px !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    min-height: 434px !important;
    height: 434px !important;
    max-height: 434px !important;
    grid-template-rows: 50px 30px 26px minmax(0, 286px) 30px !important;
  }

  body .lesson-studio .model-head,
  body .learning-flow.course-flow.lesson-studio .model-head {
    min-height: 44px !important;
    margin: 5px 8px 0 !important;
  }

  body .lesson-studio .formula-strip,
  body .learning-flow.course-flow.lesson-studio .formula-strip {
    min-height: 30px !important;
    max-height: 30px !important;
  }

  body .lesson-studio .model-feedback,
  body .learning-flow.course-flow.lesson-studio .model-feedback {
    min-height: 26px !important;
    max-height: 26px !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    min-height: 286px !important;
    height: 286px !important;
    max-height: 286px !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board,
  body .learning-flow.course-flow.lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: 30px minmax(0, 244px) !important;
    max-height: 274px !important;
  }

  body .lesson-studio .visual-stage .desktop-equation-balance,
  body .learning-flow.course-flow.lesson-studio .visual-stage .desktop-equation-balance {
    max-height: 244px !important;
  }

  body .lesson-studio .course-controls,
  body .learning-flow.course-flow.lesson-studio .course-controls {
    min-height: 30px !important;
    max-height: 30px !important;
  }

  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    min-height: 190px !important;
    height: 190px !important;
    max-height: 190px !important;
  }

  body .lesson-studio .lesson-practice .practice-list,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-list {
    grid-template-rows: 148px !important;
  }

  body .lesson-studio .lesson-practice .practice-card,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card {
    min-height: 148px !important;
    height: 148px !important;
    max-height: 148px !important;
    grid-template-rows: 18px 44px 52px 0 !important;
    padding: 9px !important;
  }

  body .lesson-studio .lesson-practice .practice-question,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question {
    min-height: 44px !important;
    height: 44px !important;
    max-height: 44px !important;
  }

  body .lesson-studio .lesson-practice .answer-options,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options {
    min-height: 52px !important;
  }

  body .lesson-studio .lesson-practice .answer-options button,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options button {
    min-height: 24px !important;
  }
}

/* Course calm10: turn the bottom row into a compact misconception + evidence + action report. */
@media (min-width: 1181px) {
  body .lesson-mistake-panel,
  body .lesson-studio .lesson-mistake-panel {
    display: grid !important;
    grid-template-columns: minmax(360px, 1fr) minmax(320px, 0.92fr) 220px !important;
    grid-template-rows: 87px !important;
    align-items: stretch !important;
    gap: 12px !important;
  }

  body .lesson-mistake-panel .mistake-card,
  body .lesson-studio .lesson-mistake-panel .mistake-card {
    grid-column: 1 !important;
    grid-row: 1 !important;
    min-height: 87px !important;
    height: 87px !important;
    max-height: 87px !important;
    border-color: rgba(240, 169, 79, 0.18) !important;
    background:
      radial-gradient(circle at 8% 0%, rgba(255, 246, 220, 0.72), transparent 36%),
      rgba(255, 252, 245, 0.82) !important;
    overflow: hidden !important;
  }

  body .lesson-mistake-panel .mistake-card p:last-child,
  body .lesson-studio .lesson-mistake-panel .mistake-card p:last-child {
    display: -webkit-box !important;
    margin: 4px 0 0 !important;
    color: #6f4b2d !important;
    font-size: 11px !important;
    line-height: 1.28 !important;
    -webkit-box-orient: vertical !important;
    -webkit-line-clamp: 2 !important;
    overflow: hidden !important;
  }

  body .lesson-mistake-panel .completion-evidence,
  body .lesson-studio .lesson-mistake-panel .completion-evidence {
    display: grid !important;
    grid-column: 2 !important;
    grid-row: 1 !important;
    min-height: 87px !important;
    height: 87px !important;
    max-height: 87px !important;
    align-content: center !important;
    gap: 5px !important;
    border-radius: 16px !important;
    background:
      radial-gradient(circle at 10% 0%, rgba(232, 247, 239, 0.76), transparent 38%),
      rgba(255, 255, 255, 0.82) !important;
    padding: 11px 13px !important;
    overflow: hidden !important;
  }

  body .lesson-mistake-panel .completion-evidence b,
  body .lesson-studio .lesson-mistake-panel .completion-evidence b {
    color: #287b73 !important;
    font-size: 12px !important;
  }

  body .lesson-mistake-panel .completion-evidence span,
  body .lesson-studio .lesson-mistake-panel .completion-evidence span {
    color: #526b7b !important;
    font-size: 11px !important;
    line-height: 1.25 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .lesson-mistake-panel .evidence-checklist,
  body .lesson-studio .lesson-mistake-panel .evidence-checklist {
    display: grid !important;
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 5px !important;
  }

  body .lesson-mistake-panel .evidence-checklist i,
  body .lesson-studio .lesson-mistake-panel .evidence-checklist i {
    justify-content: center !important;
    min-height: 22px !important;
    padding: 0 5px !important;
    font-size: 10px !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .lesson-mistake-panel .after-class-routes,
  body .lesson-studio .lesson-mistake-panel .after-class-routes {
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 5px !important;
  }

  body .lesson-mistake-panel .after-class-routes a,
  body .lesson-studio .lesson-mistake-panel .after-class-routes a {
    min-height: 30px !important;
    padding: 5px 6px !important;
  }

  body .lesson-mistake-panel .after-class-routes small,
  body .lesson-studio .lesson-mistake-panel .after-class-routes small {
    display: none !important;
  }

  body .lesson-mistake-panel .complete-button,
  body .lesson-studio .lesson-mistake-panel .complete-button {
    grid-column: 3 !important;
    grid-row: 1 !important;
    min-height: 87px !important;
    height: 87px !important;
    max-height: 87px !important;
    border-radius: 16px !important;
    font-size: 15px !important;
  }
}

/* Course calm11: make the manipulable balance fill the teaching canvas. */
@media (min-width: 1181px) {
  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    place-items: stretch !important;
    padding: 7px 9px !important;
    background:
      linear-gradient(rgba(34, 111, 227, 0.035) 1px, transparent 1px),
      linear-gradient(90deg, rgba(34, 111, 227, 0.035) 1px, transparent 1px),
      linear-gradient(180deg, rgba(247, 252, 255, 0.98), rgba(234, 247, 255, 0.9)) !important;
    background-size: 34px 34px, 34px 34px, auto !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board,
  body .learning-flow.course-flow.lesson-studio .visual-stage .equation-responsive-board {
    width: 100% !important;
    height: 100% !important;
    max-height: none !important;
    display: grid !important;
    grid-template-rows: 28px minmax(0, 242px) !important;
    gap: 4px !important;
    align-content: stretch !important;
    justify-items: stretch !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel,
  body .learning-flow.course-flow.lesson-studio .visual-stage .balance-step-panel {
    width: min(100%, 560px) !important;
    min-height: 28px !important;
    height: 28px !important;
    justify-self: center !important;
    margin: 0 !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel button,
  body .learning-flow.course-flow.lesson-studio .visual-stage .balance-step-panel button {
    min-height: 28px !important;
    height: 28px !important;
    padding: 0 18px !important;
    font-size: 12px !important;
  }

  body .lesson-studio .visual-stage .desktop-equation-balance,
  body .learning-flow.course-flow.lesson-studio .visual-stage .desktop-equation-balance {
    grid-row: 2 !important;
    width: 100% !important;
    height: 100% !important;
    max-height: none !important;
    align-self: stretch !important;
    justify-self: stretch !important;
    filter: drop-shadow(0 18px 26px rgba(38, 77, 130, 0.14)) !important;
  }

  body .lesson-studio .visual-stage .balance-equation-flow text,
  body .learning-flow.course-flow.lesson-studio .visual-stage .balance-equation-flow text {
    font-size: 12px !important;
  }
}

/* Course calm12: make the right panel match the reference lesson card structure. */
@media (min-width: 1181px) {
  body .lesson-inspector,
  body .lesson-studio .lesson-inspector {
    display: grid !important;
    grid-template-rows: 86px 74px minmax(0, 128px) 78px 72px !important;
    gap: 8px !important;
    max-height: 478px !important;
    overflow: hidden !important;
  }

  body .lesson-inspector .mini-card,
  body .lesson-studio .lesson-inspector .mini-card {
    display: grid !important;
    align-content: start !important;
    gap: 5px !important;
    min-height: 0 !important;
    padding: 10px 11px !important;
    border-radius: 16px !important;
    box-shadow: 0 10px 24px rgba(35, 63, 102, 0.045) !important;
  }

  body .lesson-inspector .lesson-target-card {
    border-color: rgba(31, 111, 229, 0.16) !important;
    background:
      radial-gradient(circle at 8% 0%, rgba(232, 244, 255, 0.88), transparent 42%),
      rgba(255, 255, 255, 0.84) !important;
  }

  body .lesson-inspector .lesson-target-card h3 {
    color: #17384a !important;
    font-size: 14px !important;
    line-height: 1.2 !important;
    margin: 0 !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
  }

  body .lesson-inspector .target-evidence {
    display: grid !important;
    grid-template-columns: 1fr !important;
    gap: 3px !important;
    min-width: 0 !important;
  }

  body .lesson-inspector .target-evidence span {
    min-width: 0 !important;
    color: #526b7b !important;
    font-size: 11px !important;
    line-height: 1.18 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .lesson-inspector .problem-card {
    background:
      linear-gradient(180deg, rgba(247, 255, 251, 0.98), rgba(235, 249, 241, 0.82)) !important;
  }

  body .lesson-inspector .problem-card h3 {
    font-size: 15px !important;
    line-height: 1.18 !important;
    -webkit-line-clamp: 2 !important;
  }

  body .lesson-inspector #solve {
    overflow: hidden !important;
  }

  body .lesson-inspector #solve ol {
    display: grid !important;
    gap: 5px !important;
    max-height: 88px !important;
    overflow: hidden !important;
  }

  body .lesson-inspector #solve li {
    grid-template-columns: 22px minmax(0, 1fr) !important;
    gap: 6px !important;
    font-size: 11px !important;
    line-height: 1.22 !important;
  }

  body .lesson-inspector #solve li b {
    width: 20px !important;
    height: 20px !important;
    border-radius: 7px !important;
  }

  body .lesson-inspector .mini-card:not(.lesson-target-card):not(.problem-card) p:not(.eyebrow),
  body .lesson-inspector .mini-card:not(.lesson-target-card):not(.problem-card) li {
    color: #425d70 !important;
  }

  body .lesson-inspector .lesson-neighbors {
    background:
      linear-gradient(180deg, rgba(246, 255, 250, 0.96), rgba(235, 248, 244, 0.84)) !important;
  }

  body .lesson-inspector .neighbor-list {
    display: grid !important;
    grid-template-columns: 1fr !important;
    gap: 4px !important;
  }

  body .lesson-inspector .neighbor-link {
    min-height: 0 !important;
    padding: 5px 7px !important;
    border-radius: 10px !important;
    grid-template-columns: minmax(58px, 0.55fr) minmax(0, 1fr) !important;
    align-items: center !important;
    gap: 5px !important;
  }

  body .lesson-inspector .neighbor-link em {
    color: #287b73 !important;
    font-size: 10px !important;
    font-style: normal !important;
    font-weight: 900 !important;
  }

  body .lesson-inspector .neighbor-link strong {
    min-width: 0 !important;
    color: #17384a !important;
    font-size: 11px !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .lesson-inspector .neighbor-link small,
  body .lesson-inspector .neighbor-link b {
    display: none !important;
  }
}

@media (max-width: 1180px) {
  .lesson-inspector .lesson-target-card {
    background: rgba(255, 255, 255, 0.78) !important;
    padding: 12px !important;
  }

  .lesson-inspector .target-evidence {
    display: grid !important;
    gap: 4px !important;
  }

  .lesson-inspector .lesson-target-card h3 {
    font-size: 16px !important;
    line-height: 1.28 !important;
  }

  .lesson-inspector .target-evidence span {
    color: #526b7b !important;
    font-size: 12px !important;
  }

  .lesson-inspector .target-evidence span:last-child {
    display: none !important;
  }
}

/* Course calm13: reduce the lesson inspector to a clear three-card teaching stack. */
@media (min-width: 1181px) {
  body .learning-flow.course-flow.lesson-studio,
  body .lesson-studio {
    grid-template-columns: 126px minmax(0, 1fr) 292px !important;
    gap: 10px !important;
  }

  body .lesson-inspector,
  body .lesson-studio .lesson-inspector {
    grid-template-rows: 112px 112px 238px !important;
    gap: 10px !important;
    max-height: 482px !important;
  }

  body .lesson-inspector .mini-card,
  body .lesson-studio .lesson-inspector .mini-card {
    border-radius: 18px !important;
    padding: 13px 14px !important;
    gap: 7px !important;
  }

  body .lesson-inspector .mini-card > .eyebrow,
  body .lesson-studio .lesson-inspector .mini-card > .eyebrow {
    color: #1f6fe5 !important;
    font-size: 12px !important;
    font-weight: 900 !important;
  }

  body .lesson-inspector .lesson-target-card {
    align-content: center !important;
    background:
      radial-gradient(circle at 0% 0%, rgba(222, 241, 255, 0.9), transparent 48%),
      linear-gradient(180deg, rgba(255, 255, 255, 0.95), rgba(244, 251, 255, 0.86)) !important;
  }

  body .lesson-inspector .lesson-target-card h3 {
    font-size: 17px !important;
    line-height: 1.24 !important;
    -webkit-line-clamp: 2 !important;
  }

  body .lesson-inspector .target-evidence {
    grid-template-columns: 1fr 1fr !important;
    gap: 6px !important;
  }

  body .lesson-inspector .target-evidence span {
    min-height: 24px !important;
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    border-radius: 999px !important;
    background: rgba(31, 111, 229, 0.08) !important;
    color: #1f5fad !important;
    font-size: 11px !important;
    font-weight: 850 !important;
  }

  body .lesson-inspector .problem-card {
    align-content: center !important;
    background:
      radial-gradient(circle at 8% 0%, rgba(226, 250, 240, 0.94), transparent 50%),
      linear-gradient(180deg, rgba(249, 255, 252, 0.98), rgba(235, 249, 241, 0.86)) !important;
  }

  body .lesson-inspector .problem-card h3 {
    color: #17384a !important;
    font-size: 18px !important;
    line-height: 1.24 !important;
    -webkit-line-clamp: 2 !important;
  }

  body .lesson-inspector #solve {
    grid-row: 3 !important;
    overflow: hidden !important;
    background:
      radial-gradient(circle at 100% 0%, rgba(244, 249, 255, 0.95), transparent 48%),
      rgba(255, 255, 255, 0.9) !important;
  }

  body .lesson-inspector #solve ol {
    max-height: none !important;
    gap: 9px !important;
  }

  body .lesson-inspector #solve li {
    grid-template-columns: 26px minmax(0, 1fr) !important;
    gap: 8px !important;
    color: #2f4d62 !important;
    font-size: 12px !important;
    line-height: 1.34 !important;
  }

  body .lesson-inspector #solve li b {
    width: 24px !important;
    height: 24px !important;
    border-radius: 9px !important;
    background: #eaf3ff !important;
    color: #1f6fe5 !important;
  }

  body .lesson-inspector > .mini-card:not(.lesson-target-card):not(.problem-card):not(#solve),
  body .lesson-inspector .lesson-neighbors {
    display: none !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    border-radius: 24px !important;
    box-shadow: 0 22px 58px rgba(35, 71, 112, 0.07) !important;
  }

  body .lesson-studio .model-head h2,
  body .learning-flow.course-flow.lesson-studio .model-head h2 {
    font-size: 20px !important;
    line-height: 1.2 !important;
  }
}

@media (max-width: 1180px) {
  .lesson-inspector > .mini-card:not(.lesson-target-card):not(.problem-card):not(#solve),
  .lesson-inspector .lesson-neighbors {
    display: none !important;
  }

  .lesson-inspector #solve {
    border-radius: 18px !important;
    background: rgba(255, 255, 255, 0.82) !important;
  }
}

/* Course calm14: make transfer practice read like a diagnosis zone, not four equal chips. */
@media (min-width: 1181px) {
  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    height: 210px !important;
    min-height: 210px !important;
    max-height: 210px !important;
    grid-template-columns: 178px minmax(0, 1fr) !important;
    padding: 13px 14px !important;
    border-radius: 24px !important;
    background:
      radial-gradient(circle at 0% 0%, rgba(232, 244, 255, 0.78), transparent 42%),
      rgba(255, 255, 255, 0.86) !important;
    box-shadow: 0 18px 46px rgba(35, 71, 112, 0.055) !important;
    overflow: hidden !important;
  }

  body .lesson-studio .lesson-practice > div:first-child,
  body .learning-flow.course-flow.lesson-studio .lesson-practice > div:first-child {
    display: grid !important;
    align-content: center !important;
    gap: 7px !important;
    padding-right: 14px !important;
    border-right: 1px solid rgba(64, 111, 178, 0.12) !important;
  }

  body .lesson-studio .lesson-practice h2,
  body .learning-flow.course-flow.lesson-studio .lesson-practice h2 {
    font-size: 21px !important;
    line-height: 1.18 !important;
    color: #173047 !important;
  }

  body .lesson-studio .lesson-practice .practice-list,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-list {
    display: grid !important;
    grid-template-columns: minmax(330px, 1.45fr) repeat(3, minmax(0, 0.82fr)) !important;
    grid-template-rows: 174px !important;
    gap: 10px !important;
    min-width: 0 !important;
  }

  body .lesson-studio .lesson-practice .practice-card,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card {
    height: 174px !important;
    min-height: 174px !important;
    max-height: 174px !important;
    display: grid !important;
    grid-template-rows: 24px minmax(0, 48px) minmax(0, 64px) 0 !important;
    gap: 7px !important;
    padding: 11px !important;
    border-radius: 17px !important;
    background: rgba(255, 255, 255, 0.78) !important;
    border-color: rgba(64, 111, 178, 0.12) !important;
    overflow: hidden !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child {
    grid-template-rows: 24px minmax(0, 50px) minmax(0, 60px) 26px !important;
    padding: 12px !important;
    border-color: rgba(31, 111, 229, 0.18) !important;
    background:
      radial-gradient(circle at 100% 0%, rgba(237, 247, 255, 0.92), transparent 45%),
      linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(245, 250, 255, 0.9)) !important;
  }

  body .lesson-studio .lesson-practice .practice-card-head,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card-head {
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 6px !important;
    min-height: 24px !important;
  }

  body .lesson-studio .lesson-practice .practice-card-head span,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card-head span {
    display: inline-flex !important;
    align-items: center !important;
    height: 22px !important;
    padding: 0 8px !important;
    border-radius: 999px !important;
    background: rgba(31, 111, 229, 0.1) !important;
    color: #1f6fe5 !important;
    font-size: 11px !important;
    font-weight: 900 !important;
  }

  body .lesson-studio .lesson-practice .practice-card-head em,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card-head em,
  body .lesson-studio .lesson-practice .practice-question span,
  body .lesson-studio .lesson-practice .practice-question small,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question span,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question small {
    display: none !important;
  }

  body .lesson-studio .lesson-practice .practice-question,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question {
    min-height: 0 !important;
    height: auto !important;
    overflow: hidden !important;
  }

  body .lesson-studio .lesson-practice .practice-question strong,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-question strong {
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    overflow: hidden !important;
    color: #122a43 !important;
    font-size: 12px !important;
    line-height: 1.24 !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child .practice-question strong,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .practice-question strong {
    font-size: 14px !important;
    line-height: 1.25 !important;
  }

  body .lesson-studio .lesson-practice .answer-options,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options {
    display: grid !important;
    grid-template-columns: repeat(2, minmax(0, 1fr)) !important;
    gap: 6px !important;
    min-height: 0 !important;
  }

  body .lesson-studio .lesson-practice .answer-options button,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .answer-options button {
    min-height: 27px !important;
    max-height: none !important;
    padding: 4px 7px !important;
    border-radius: 11px !important;
    font-size: 11px !important;
    line-height: 1.16 !important;
    font-weight: 850 !important;
    white-space: normal !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child .answer-options button,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .answer-options button {
    min-height: 28px !important;
    font-size: 12px !important;
  }

  body .lesson-studio .lesson-practice .practice-diagnosis,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-diagnosis {
    display: none !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child .practice-diagnosis,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .practice-diagnosis {
    display: flex !important;
    align-items: center !important;
    gap: 6px !important;
    min-height: 24px !important;
    padding: 0 8px !important;
    border-radius: 999px !important;
    background: rgba(40, 123, 115, 0.08) !important;
    overflow: hidden !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child .practice-diagnosis b,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .practice-diagnosis b {
    display: inline-block !important;
    color: #287b73 !important;
    font-size: 11px !important;
    font-weight: 900 !important;
    line-height: 1 !important;
    white-space: nowrap !important;
  }

  body .lesson-studio .lesson-practice .practice-card:first-child .practice-diagnosis span,
  body .lesson-studio .lesson-practice .practice-card:first-child .practice-diagnosis a,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .practice-diagnosis span,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card:first-child .practice-diagnosis a {
    display: none !important;
  }

  body .lesson-mistake-panel,
  body .lesson-studio .lesson-mistake-panel {
    margin-top: 4px !important;
  }
}

@media (max-width: 1180px) {
  .lesson-practice .practice-card-head,
  .lesson-practice .practice-diagnosis {
    display: none !important;
  }
}

/* Course calm15: turn the bottom row into a compact mistake-to-mastery diagnostic band. */
@media (min-width: 1181px) {
  body .lesson-mistake-panel,
  body .lesson-studio .lesson-mistake-panel {
    display: grid !important;
    grid-template-columns: minmax(400px, 1.1fr) minmax(360px, 1fr) 220px !important;
    grid-template-rows: 91px !important;
    gap: 10px !important;
    align-items: stretch !important;
    margin-top: 6px !important;
    min-height: 91px !important;
    height: 91px !important;
    max-height: 91px !important;
    overflow: visible !important;
  }

  body .lesson-mistake-panel .mistake-card,
  body .lesson-studio .lesson-mistake-panel .mistake-card {
    display: grid !important;
    grid-column: 1 !important;
    grid-row: 1 !important;
    align-content: center !important;
    gap: 6px !important;
    min-height: 91px !important;
    height: 91px !important;
    max-height: 91px !important;
    padding: 13px 16px !important;
    border-radius: 18px !important;
    border-color: rgba(240, 169, 79, 0.2) !important;
    background:
      radial-gradient(circle at 0% 0%, rgba(255, 244, 218, 0.9), transparent 42%),
      linear-gradient(180deg, rgba(255, 253, 248, 0.98), rgba(255, 247, 232, 0.9)) !important;
    overflow: hidden !important;
  }

  body .lesson-mistake-panel .mistake-card .eyebrow,
  body .lesson-studio .lesson-mistake-panel .mistake-card .eyebrow {
    color: #a66317 !important;
    font-size: 12px !important;
    font-weight: 900 !important;
  }

  body .lesson-mistake-panel .mistake-card p:last-child,
  body .lesson-studio .lesson-mistake-panel .mistake-card p:last-child {
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    margin: 0 !important;
    color: #5f462f !important;
    font-size: 12px !important;
    line-height: 1.38 !important;
    overflow: hidden !important;
  }

  body .lesson-mistake-panel .completion-evidence,
  body .lesson-studio .lesson-mistake-panel .completion-evidence {
    display: grid !important;
    grid-column: 2 !important;
    grid-row: 1 !important;
    align-content: center !important;
    gap: 6px !important;
    min-height: 91px !important;
    height: 91px !important;
    max-height: 91px !important;
    padding: 12px 14px !important;
    border-radius: 18px !important;
    border-color: rgba(40, 123, 115, 0.16) !important;
    background:
      radial-gradient(circle at 100% 0%, rgba(228, 249, 240, 0.9), transparent 42%),
      rgba(255, 255, 255, 0.86) !important;
    overflow: hidden !important;
  }

  body .lesson-mistake-panel .completion-evidence b,
  body .lesson-studio .lesson-mistake-panel .completion-evidence b {
    color: #287b73 !important;
    font-size: 13px !important;
    line-height: 1.05 !important;
    font-weight: 920 !important;
  }

  body .lesson-mistake-panel .completion-evidence span,
  body .lesson-studio .lesson-mistake-panel .completion-evidence span {
    display: block !important;
    color: #506a77 !important;
    font-size: 11px !important;
    line-height: 1.22 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .lesson-mistake-panel .evidence-checklist,
  body .lesson-studio .lesson-mistake-panel .evidence-checklist {
    display: grid !important;
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 5px !important;
  }

  body .lesson-mistake-panel .evidence-checklist i,
  body .lesson-studio .lesson-mistake-panel .evidence-checklist i {
    min-width: 0 !important;
    min-height: 22px !important;
    justify-content: center !important;
    padding: 0 6px !important;
    border-radius: 999px !important;
    font-size: 10px !important;
    font-style: normal !important;
    font-weight: 850 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .lesson-mistake-panel .after-class-routes,
  body .lesson-studio .lesson-mistake-panel .after-class-routes {
    display: grid !important;
    grid-template-columns: repeat(3, minmax(0, 1fr)) !important;
    gap: 5px !important;
  }

  body .lesson-mistake-panel .after-class-routes a,
  body .lesson-studio .lesson-mistake-panel .after-class-routes a {
    min-height: 28px !important;
    padding: 4px 6px !important;
    border-radius: 10px !important;
  }

  body .lesson-mistake-panel .after-class-routes strong,
  body .lesson-studio .lesson-mistake-panel .after-class-routes strong {
    font-size: 11px !important;
    line-height: 1.1 !important;
  }

  body .lesson-mistake-panel .after-class-routes small,
  body .lesson-studio .lesson-mistake-panel .after-class-routes small {
    display: none !important;
  }

  body .lesson-mistake-panel .complete-button,
  body .lesson-studio .lesson-mistake-panel .complete-button {
    grid-column: 3 !important;
    grid-row: 1 !important;
    min-height: 91px !important;
    height: 91px !important;
    max-height: 91px !important;
    border-radius: 18px !important;
    font-size: 15px !important;
    line-height: 1.25 !important;
    box-shadow: 0 18px 38px rgba(31, 111, 229, 0.16) !important;
  }
}

@media (max-width: 1180px) {
  .lesson-mistake-panel {
    gap: 10px !important;
  }

  .lesson-mistake-panel .mistake-card {
    background: rgba(255, 251, 244, 0.86) !important;
  }
}

/* Course calm16: make the lesson cockpit closer to the reference, with a larger central teaching canvas. */
@media (min-width: 1181px) {
  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main {
    display: grid !important;
    grid-template-rows: 72px 466px !important;
    gap: 10px !important;
    min-height: 548px !important;
    height: 548px !important;
    max-height: 548px !important;
    overflow: visible !important;
  }

  body .lesson-main .course-prompt,
  body .lesson-studio .course-prompt {
    display: grid !important;
    grid-template-columns: minmax(280px, 1fr) auto minmax(180px, 240px) !important;
    align-items: center !important;
    gap: 10px !important;
    min-height: 72px !important;
    height: 72px !important;
    max-height: 72px !important;
    padding: 14px 14px !important;
    border-radius: 22px !important;
    background:
      radial-gradient(circle at 0% 0%, rgba(232, 244, 255, 0.82), transparent 42%),
      rgba(255, 255, 255, 0.82) !important;
    box-shadow: 0 14px 34px rgba(35, 71, 112, 0.05) !important;
    overflow: visible !important;
  }

  body .lesson-main .course-prompt .eyebrow,
  body .lesson-studio .course-prompt .eyebrow {
    display: none !important;
  }

  body .lesson-main .course-prompt h2,
  body .lesson-studio .course-prompt h2 {
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    min-width: 0 !important;
    align-self: center !important;
    max-height: 40px !important;
    margin: 0 !important;
    color: #142d45 !important;
    font-size: 16px !important;
    line-height: 1.22 !important;
    white-space: normal !important;
    overflow: hidden !important;
  }

  body .lesson-main .course-prompt .choice-row,
  body .lesson-studio .course-prompt .choice-row {
    display: flex !important;
    flex-wrap: nowrap !important;
    justify-content: flex-end !important;
    gap: 7px !important;
    min-width: 0 !important;
  }

  body .lesson-main .course-prompt .choice-row button,
  body .lesson-studio .course-prompt .choice-row button {
    min-width: 112px !important;
    min-height: 34px !important;
    padding: 0 12px !important;
    border-radius: 14px !important;
    font-size: 12px !important;
    line-height: 1.1 !important;
    white-space: nowrap !important;
  }

  body .lesson-main .course-prompt .feedback,
  body .lesson-studio .course-prompt .feedback {
    display: block !important;
    min-width: 0 !important;
    margin: 0 !important;
    color: #46616f !important;
    font-size: 11px !important;
    line-height: 1.2 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    min-height: 466px !important;
    height: 466px !important;
    max-height: 466px !important;
    grid-template-rows: 46px 28px 24px minmax(0, 332px) 26px !important;
    border-radius: 26px !important;
    background:
      radial-gradient(circle at 100% 0%, rgba(229, 247, 241, 0.88), transparent 40%),
      rgba(255, 255, 255, 0.88) !important;
    box-shadow: 0 26px 68px rgba(35, 71, 112, 0.08) !important;
    overflow: hidden !important;
  }

  body .lesson-studio .model-head,
  body .learning-flow.course-flow.lesson-studio .model-head {
    min-height: 42px !important;
    margin: 5px 8px 0 !important;
    padding: 7px 10px !important;
    border-radius: 16px !important;
  }

  body .lesson-studio .model-head h2,
  body .learning-flow.course-flow.lesson-studio .model-head h2 {
    font-size: 19px !important;
    line-height: 1.16 !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
  }

  body .lesson-studio .formula-strip,
  body .learning-flow.course-flow.lesson-studio .formula-strip {
    min-height: 28px !important;
    max-height: 28px !important;
  }

  body .lesson-studio .model-feedback,
  body .learning-flow.course-flow.lesson-studio .model-feedback {
    min-height: 24px !important;
    max-height: 24px !important;
    font-size: 12px !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    min-height: 332px !important;
    height: 332px !important;
    max-height: 332px !important;
    padding: 8px 10px !important;
    border-radius: 20px !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board,
  body .learning-flow.course-flow.lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: 30px minmax(0, 282px) !important;
    gap: 4px !important;
    max-height: none !important;
  }

  body .lesson-studio .visual-stage .desktop-equation-balance,
  body .learning-flow.course-flow.lesson-studio .visual-stage .desktop-equation-balance {
    max-height: none !important;
    height: 100% !important;
  }

  body .lesson-studio .course-controls,
  body .learning-flow.course-flow.lesson-studio .course-controls {
    min-height: 26px !important;
    max-height: 26px !important;
  }

  body .lesson-studio .lesson-inspector {
    grid-template-rows: 112px 112px 238px !important;
    max-height: 482px !important;
  }

  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    min-height: 184px !important;
    height: 184px !important;
    max-height: 184px !important;
  }

  body .lesson-studio .lesson-practice .practice-list,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-list {
    grid-template-rows: 148px !important;
  }

  body .lesson-studio .lesson-practice .practice-card,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card {
    min-height: 148px !important;
    height: 148px !important;
    max-height: 148px !important;
    grid-template-rows: 22px minmax(0, 40px) minmax(0, 54px) 22px !important;
  }

  body .lesson-mistake-panel,
  body .lesson-studio .lesson-mistake-panel {
    grid-template-rows: 82px !important;
    min-height: 82px !important;
    height: 82px !important;
    max-height: 82px !important;
    margin-top: 4px !important;
  }

  body .lesson-mistake-panel .mistake-card,
  body .lesson-mistake-panel .completion-evidence,
  body .lesson-mistake-panel .complete-button,
  body .lesson-studio .lesson-mistake-panel .mistake-card,
  body .lesson-studio .lesson-mistake-panel .completion-evidence,
  body .lesson-studio .lesson-mistake-panel .complete-button {
    min-height: 82px !important;
    height: 82px !important;
    max-height: 82px !important;
  }
}

/* Course calm17: give the bottom diagnosis band enough air while preserving the large central model. */
@media (min-width: 1181px) {
  body .lesson-studio,
  body .learning-flow.course-flow.lesson-studio {
    grid-template-rows: 548px 176px 96px !important;
  }

  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    min-height: 176px !important;
    height: 176px !important;
    max-height: 176px !important;
    padding: 13px !important;
  }

  body .lesson-studio .lesson-practice .practice-list,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-list {
    grid-template-rows: 140px !important;
  }

  body .lesson-studio .lesson-practice .practice-card,
  body .learning-flow.course-flow.lesson-studio .lesson-practice .practice-card {
    min-height: 140px !important;
    height: 140px !important;
    max-height: 140px !important;
    grid-template-rows: 20px minmax(0, 38px) minmax(0, 52px) 20px !important;
  }

  body .lesson-mistake-panel,
  body .lesson-studio .lesson-mistake-panel {
    grid-template-rows: 96px !important;
    min-height: 96px !important;
    height: 96px !important;
    max-height: 96px !important;
    margin-top: 2px !important;
  }

  body .lesson-mistake-panel .mistake-card,
  body .lesson-mistake-panel .completion-evidence,
  body .lesson-mistake-panel .complete-button,
  body .lesson-studio .lesson-mistake-panel .mistake-card,
  body .lesson-studio .lesson-mistake-panel .completion-evidence,
  body .lesson-studio .lesson-mistake-panel .complete-button {
    min-height: 96px !important;
    height: 96px !important;
    max-height: 96px !important;
  }

  body .lesson-mistake-panel .mistake-card,
  body .lesson-studio .lesson-mistake-panel .mistake-card {
    gap: 7px !important;
    padding: 12px 14px !important;
  }

  body .lesson-mistake-panel .mistake-card p:last-child,
  body .lesson-studio .lesson-mistake-panel .mistake-card p:last-child {
    -webkit-line-clamp: 2 !important;
    font-size: 12px !important;
    line-height: 1.42 !important;
  }

  body .lesson-mistake-panel .completion-evidence,
  body .lesson-studio .lesson-mistake-panel .completion-evidence {
    gap: 7px !important;
    padding: 12px 14px !important;
  }

  body .lesson-mistake-panel .completion-evidence span,
  body .lesson-studio .lesson-mistake-panel .completion-evidence span {
    line-height: 1.28 !important;
  }

  body .lesson-mistake-panel .complete-button,
  body .lesson-studio .lesson-mistake-panel .complete-button {
    min-height: 96px !important;
    height: 96px !important;
    max-height: 96px !important;
    border-radius: 20px !important;
  }
}

/* Course calm18: make the prediction task strip readable without collapsing the main model. */
@media (min-width: 1181px) {
  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main {
    grid-template-rows: 82px 456px !important;
    min-height: 548px !important;
    height: 548px !important;
    max-height: 548px !important;
  }

  body .lesson-main .course-prompt,
  body .lesson-studio .course-prompt {
    grid-template-columns: minmax(310px, 1fr) auto minmax(160px, 220px) !important;
    min-height: 82px !important;
    height: 82px !important;
    max-height: 82px !important;
    padding: 15px 16px !important;
    align-items: center !important;
  }

  body .lesson-main .course-prompt h2,
  body .lesson-studio .course-prompt h2 {
    max-height: 48px !important;
    font-size: 17px !important;
    line-height: 1.28 !important;
    -webkit-line-clamp: 2 !important;
  }

  body .lesson-main .course-prompt .choice-row,
  body .lesson-studio .course-prompt .choice-row {
    align-self: center !important;
  }

  body .lesson-main .course-prompt .choice-row button,
  body .lesson-studio .course-prompt .choice-row button {
    min-width: 112px !important;
    min-height: 36px !important;
  }

  body .lesson-main .course-prompt .feedback,
  body .lesson-studio .course-prompt .feedback {
    white-space: normal !important;
    display: -webkit-box !important;
    -webkit-line-clamp: 2 !important;
    -webkit-box-orient: vertical !important;
    max-height: 34px !important;
    font-size: 11px !important;
    line-height: 1.32 !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    min-height: 456px !important;
    height: 456px !important;
    max-height: 456px !important;
    grid-template-rows: 44px 28px 24px minmax(0, 322px) 26px !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    min-height: 322px !important;
    height: 322px !important;
    max-height: 322px !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board,
  body .learning-flow.course-flow.lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: 30px minmax(0, 272px) !important;
  }
}

/* Course calm19: prediction strip uses a clean question/actions layout. */
@media (min-width: 1181px) {
  body .lesson-main .course-prompt,
  body .lesson-studio .course-prompt {
    grid-template-columns: minmax(430px, 1fr) auto !important;
    column-gap: 16px !important;
  }

  body .lesson-main .course-prompt h2,
  body .lesson-studio .course-prompt h2 {
    max-width: 520px !important;
    font-size: 17px !important;
    line-height: 1.28 !important;
  }

  body .lesson-main .course-prompt .choice-row,
  body .lesson-studio .course-prompt .choice-row {
    justify-content: end !important;
    justify-self: end !important;
  }

  body .lesson-main .course-prompt .feedback,
  body .lesson-studio .course-prompt .feedback {
    display: none !important;
  }
}

/* Course calm20: reference-style lesson workbench, bigger model and cleaner support panels. */
@media (min-width: 1181px) {
  body .course-system-shell {
    background:
      radial-gradient(circle at 55% -18%, rgba(220, 239, 255, 0.74), transparent 38%),
      linear-gradient(180deg, #f8fbff 0%, #eef8f5 100%) !important;
  }

  body .lesson-studio-shell .course-hero {
    min-height: 62px !important;
    height: 62px !important;
    padding: 10px 18px !important;
    border-radius: 22px !important;
  }

  body .lesson-studio-shell .course-hero h1 {
    font-size: 31px !important;
    line-height: 1.05 !important;
  }

  body .learning-flow.course-flow.lesson-studio,
  body .lesson-studio {
    grid-template-columns: 138px minmax(0, 1fr) 302px !important;
    grid-template-rows: 550px 168px 92px !important;
    gap: 10px !important;
    height: 810px !important;
    max-height: 810px !important;
  }

  body .lesson-stepper {
    width: 138px !important;
    padding: 8px !important;
    border-radius: 24px !important;
    background: rgba(255, 255, 255, 0.66) !important;
    box-shadow: 0 20px 52px rgba(46, 78, 94, 0.05) !important;
  }

  body .lesson-stepper a {
    min-height: 58px !important;
    border-radius: 18px !important;
    grid-template-columns: 30px minmax(0, 1fr) !important;
    padding: 8px !important;
  }

  body .lesson-stepper a span {
    font-size: 12px !important;
    line-height: 1.15 !important;
    white-space: normal !important;
    overflow: visible !important;
    text-overflow: clip !important;
  }

  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main {
    grid-template-rows: 72px 468px !important;
    height: 550px !important;
    min-height: 550px !important;
    max-height: 550px !important;
    gap: 10px !important;
  }

  body .lesson-main .course-prompt,
  body .lesson-studio .course-prompt {
    min-height: 72px !important;
    height: 72px !important;
    max-height: 72px !important;
    border-radius: 22px !important;
    padding: 12px 14px !important;
    background: rgba(255, 255, 255, 0.8) !important;
    box-shadow: 0 18px 42px rgba(45, 82, 98, 0.045) !important;
  }

  body .lesson-main .course-prompt h2,
  body .lesson-studio .course-prompt h2 {
    max-width: 560px !important;
    font-size: 18px !important;
    line-height: 1.22 !important;
  }

  body .lesson-main .course-prompt .choice-row button,
  body .lesson-studio .course-prompt .choice-row button {
    min-height: 34px !important;
    border-radius: 14px !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    min-height: 468px !important;
    height: 468px !important;
    max-height: 468px !important;
    grid-template-rows: 42px 26px 22px minmax(0, 350px) 18px !important;
    border-radius: 28px !important;
    padding: 14px !important;
    box-shadow: 0 24px 70px rgba(42, 80, 96, 0.06) !important;
  }

  body .lesson-studio .model-head h2 {
    font-size: 24px !important;
    line-height: 1.13 !important;
  }

  body .lesson-studio .formula-strip {
    min-height: 26px !important;
    height: 26px !important;
  }

  body .lesson-studio .model-feedback {
    min-height: 22px !important;
    height: 22px !important;
    font-size: 12px !important;
    line-height: 1.2 !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    min-height: 350px !important;
    height: 350px !important;
    max-height: 350px !important;
    border-radius: 24px !important;
  }

  body .lesson-studio .visual-stage .equation-responsive-board,
  body .learning-flow.course-flow.lesson-studio .visual-stage .equation-responsive-board {
    grid-template-rows: 30px minmax(0, 300px) !important;
  }

  body .lesson-inspector {
    width: 302px !important;
    height: 550px !important;
    min-height: 550px !important;
    max-height: 550px !important;
    grid-template-rows: 102px 104px minmax(0, 178px) 70px 62px !important;
    gap: 9px !important;
    padding: 0 !important;
    background: transparent !important;
    box-shadow: none !important;
  }

  body .lesson-inspector .mini-card {
    border-radius: 22px !important;
    background: rgba(255, 255, 255, 0.78) !important;
    box-shadow: 0 18px 42px rgba(42, 80, 96, 0.045) !important;
    padding: 14px !important;
    overflow: hidden !important;
  }

  body .lesson-inspector .mini-card h3 {
    font-size: 18px !important;
    line-height: 1.2 !important;
  }

  body .lesson-inspector .mini-card p,
  body .lesson-inspector .mini-card li {
    font-size: 12px !important;
    line-height: 1.36 !important;
  }

  body .lesson-inspector #solutionSteps {
    gap: 7px !important;
  }

  body .lesson-inspector #solutionSteps li {
    grid-template-columns: 24px minmax(0, 1fr) !important;
    padding: 0 !important;
  }

  body .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    height: 168px !important;
    min-height: 168px !important;
    max-height: 168px !important;
    grid-template-columns: 178px minmax(0, 1fr) !important;
    padding: 12px !important;
    border-radius: 26px !important;
    background: rgba(255, 255, 255, 0.78) !important;
    box-shadow: 0 20px 52px rgba(42, 80, 96, 0.05) !important;
  }

  body .lesson-practice h2 {
    font-size: 22px !important;
    line-height: 1.13 !important;
  }

  body .lesson-practice .practice-list {
    grid-template-rows: 132px !important;
    gap: 10px !important;
  }

  body .lesson-practice .practice-card {
    min-height: 132px !important;
    height: 132px !important;
    max-height: 132px !important;
    border-radius: 18px !important;
    grid-template-rows: 20px minmax(0, 36px) minmax(0, 48px) 18px !important;
    padding: 10px !important;
  }

  body .lesson-practice .practice-question strong {
    -webkit-line-clamp: 2 !important;
    font-size: 13px !important;
    line-height: 1.25 !important;
  }

  body .lesson-mistake-panel,
  body .lesson-studio .lesson-mistake-panel {
    height: 92px !important;
    min-height: 92px !important;
    max-height: 92px !important;
    grid-template-columns: minmax(0, 1fr) minmax(260px, 0.62fr) 220px !important;
    gap: 10px !important;
  }

  body .lesson-mistake-panel .mistake-card,
  body .lesson-mistake-panel .completion-evidence,
  body .lesson-mistake-panel .complete-button {
    height: 92px !important;
    min-height: 92px !important;
    max-height: 92px !important;
    border-radius: 20px !important;
  }
}

/* Course calm23: make equation solving read as a visible balance-action trail. */
.lesson-inspector #solutionSteps .equation-trail-step {
  display: grid !important;
  grid-template-columns: 24px minmax(0, 1fr) !important;
  gap: 8px !important;
  align-items: start !important;
  padding: 7px 8px !important;
  border-radius: 14px !important;
  border: 1px solid rgba(91, 125, 145, 0.12) !important;
  background: rgba(247, 251, 253, 0.64) !important;
}

.lesson-inspector #solutionSteps .equation-trail-step b {
  width: 24px !important;
  height: 24px !important;
  display: grid !important;
  place-items: center !important;
  border-radius: 999px !important;
  background: rgba(47, 114, 214, 0.1) !important;
  color: #1f6fdf !important;
  font-size: 12px !important;
  font-weight: 950 !important;
}

.lesson-inspector #solutionSteps .equation-trail-step span {
  display: grid !important;
  gap: 3px !important;
  min-width: 0 !important;
}

.lesson-inspector #solutionSteps .equation-trail-step strong {
  color: #173047 !important;
  font-size: 13px !important;
  font-weight: 950 !important;
  line-height: 1.1 !important;
  white-space: nowrap !important;
  overflow: hidden !important;
  text-overflow: ellipsis !important;
}

.lesson-inspector #solutionSteps .equation-trail-step small {
  color: #617884 !important;
  font-size: 11px !important;
  font-weight: 760 !important;
  line-height: 1.28 !important;
}

.lesson-inspector #solutionSteps .equation-trail-step.is-current {
  border-color: rgba(47, 114, 214, 0.28) !important;
  background: linear-gradient(135deg, rgba(232, 243, 255, 0.9), rgba(239, 249, 247, 0.84)) !important;
  box-shadow: 0 10px 26px rgba(47, 114, 214, 0.08) !important;
}

.lesson-inspector #solutionSteps .equation-trail-step.is-current b {
  background: linear-gradient(145deg, #66a7ff, #2f72d6) !important;
  color: #fff !important;
}

.lesson-inspector #solutionSteps .equation-trail-step.is-locked {
  opacity: 0.58 !important;
}

/* Course function1: G7-F03 uses a tactile triple-view function lab. */
.function-lab {
  width: 100%;
  min-height: 100%;
  display: grid;
  grid-template-columns: minmax(180px, .78fr) minmax(300px, 1.28fr) minmax(150px, .62fr);
  gap: 12px;
  align-items: stretch;
  padding: 10px;
}

.function-lab section {
  min-width: 0;
  border: 1px solid rgba(55, 89, 112, .12);
  border-radius: 22px;
  background:
    radial-gradient(circle at 18% 0%, rgba(255, 255, 255, .98), transparent 44%),
    linear-gradient(180deg, rgba(255, 255, 255, .88), rgba(239, 249, 247, .76));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, .92),
    0 18px 42px rgba(45, 82, 98, .075);
}

.function-machine-panel {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  grid-template-rows: 24px repeat(2, minmax(0, 1fr)) 34px;
  gap: 8px;
  padding: 14px;
}

.machine-label,
.machine-rule {
  grid-column: 1 / -1;
  display: grid;
  place-items: center;
  color: #173047;
  font-weight: 950;
}

.machine-label {
  font-size: 13px;
  letter-spacing: 0;
}

.machine-rule {
  min-height: 34px;
  border-radius: 16px;
  background: rgba(255, 213, 0, .18);
  color: #745d00;
  font-size: 16px;
}

.machine-step {
  min-width: 0;
  display: grid;
  place-items: center;
  gap: 3px;
  border: 1px solid rgba(31, 111, 229, .12);
  border-radius: 20px;
  background: rgba(255, 255, 255, .72);
  box-shadow: 0 14px 28px rgba(45, 82, 98, .06);
  padding: 8px 6px;
}

.machine-step b,
.machine-step small {
  color: #647884;
  font-size: 12px;
  font-weight: 850;
}

.machine-step strong {
  color: #173047;
  font-size: clamp(24px, 3vw, 36px);
  font-weight: 950;
  line-height: 1;
}

.machine-step.is-input {
  grid-column: 1;
  grid-row: 2 / 4;
}

.machine-step.is-multiply {
  grid-column: 3;
  grid-row: 2;
}

.machine-step.is-add {
  grid-column: 3;
  grid-row: 3;
}

.machine-arrow {
  display: grid;
  place-items: center;
  color: #1f6fdf;
  font-size: 24px;
  font-weight: 950;
}

.function-graph-panel {
  display: grid;
  place-items: center;
  padding: 8px;
}

.function-machine-graph {
  width: 100%;
  max-height: 316px;
  touch-action: none;
}

.graph-surface {
  fill: rgba(255, 255, 255, .72);
  stroke: rgba(57, 88, 109, .12);
}

.graph-grid {
  stroke: rgba(91, 125, 145, .13);
  stroke-width: 1;
}

.graph-axis {
  stroke: rgba(23, 48, 71, .54);
  stroke-width: 2;
}

.function-line {
  fill: none;
  stroke: #1f6fdf;
  stroke-width: 5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.function-guide {
  stroke: rgba(255, 213, 0, .78);
  stroke-width: 3;
  stroke-dasharray: 7 7;
}

.function-point {
  cursor: grab;
  touch-action: none;
}

.function-point:active,
.function-point.is-dragging-source {
  cursor: grabbing;
}

.point-halo {
  fill: rgba(31, 111, 229, .14);
  stroke: rgba(255, 255, 255, .8);
  stroke-width: 4;
}

.point-dot {
  fill: #1f6fdf;
  stroke: #fff;
  stroke-width: 4;
}

.point-label,
.graph-note {
  fill: #173047;
  font-size: 13px;
  font-weight: 900;
}

.point-label-plate {
  fill: rgba(255, 255, 255, 0.82);
  stroke: rgba(91, 125, 145, 0.12);
  stroke-width: 1;
}

.function-table-panel {
  display: grid;
  grid-template-rows: 30px repeat(7, minmax(0, 1fr)) 28px;
  gap: 5px;
  padding: 12px;
}

.function-table-panel div {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  min-height: 0;
  border-radius: 12px;
  color: #173047;
  font-size: 13px;
  font-weight: 900;
  text-align: center;
}

.function-table-panel .table-head {
  background: rgba(23, 48, 71, .08);
  color: #5c717d;
}

.function-table-panel div:not(.table-head) {
  background: rgba(255, 255, 255, .64);
  border: 1px solid rgba(91, 125, 145, .1);
}

.function-table-panel div.is-active {
  background: rgba(255, 213, 0, .2);
  border-color: rgba(255, 213, 0, .46);
  box-shadow: 0 10px 24px rgba(255, 213, 0, .12);
}

.function-table-panel p {
  margin: 0;
  align-self: end;
  color: #5f7580;
  font-size: 11px;
  font-weight: 780;
  line-height: 1.2;
}

@media (max-width: 900px) {
  body .lesson-studio .visual-stage:has(.function-lab),
  body .learning-flow.course-flow.lesson-studio .visual-stage:has(.function-lab) {
    height: auto !important;
    max-height: none !important;
    min-height: 760px !important;
    overflow: visible !important;
  }

  .function-lab {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
    gap: 10px;
    padding: 8px;
  }

  .function-machine-panel {
    min-height: 250px;
    grid-template-columns: 1fr;
    grid-template-rows: 22px repeat(3, 52px) 32px;
    gap: 6px;
  }

  .machine-step.is-input,
  .machine-step.is-multiply,
  .machine-step.is-add,
  .machine-rule,
  .machine-label {
    grid-column: 1;
    grid-row: auto;
  }

  .machine-step {
    grid-template-columns: 54px 1fr 54px;
    padding: 6px 10px;
  }

  .machine-step strong {
    font-size: 28px;
  }

  .machine-arrow {
    display: none;
  }

  .function-machine-graph {
    max-height: 230px;
  }

  .function-table-panel {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    grid-template-rows: auto;
  }

  .function-table-panel .table-head,
  .function-table-panel p {
    grid-column: 1 / -1;
  }
}

/* Course mobile-gate1: final mobile override prevents the desktop 3-column shell from clipping lesson content. */
@media (max-width: 760px) {
  html,
  body {
    max-width: 100vw !important;
    overflow-x: hidden !important;
  }

  body .learning-flow.course-flow.lesson-studio,
  body .lesson-studio {
    width: 100% !important;
    max-width: 100vw !important;
    height: auto !important;
    max-height: none !important;
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) !important;
    grid-template-rows: auto !important;
    gap: 10px !important;
    overflow: visible !important;
  }

  body .lesson-stepper {
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    display: flex !important;
    gap: 8px !important;
    overflow-x: auto !important;
    padding: 8px !important;
  }

  body .lesson-stepper a {
    flex: 0 0 132px !important;
  }

  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main,
  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card,
  body .lesson-studio .lesson-inspector,
  body .learning-flow.course-flow.lesson-studio .lesson-inspector,
  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice,
  body .lesson-studio .lesson-mistake-panel,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel {
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    height: auto !important;
    max-height: none !important;
  }

  body .lesson-main .course-prompt,
  body .lesson-studio .course-prompt {
    height: auto !important;
    max-height: none !important;
    min-height: 0 !important;
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) !important;
  }

  body .lesson-studio .course-prompt .choice-row {
    grid-column: 1 !important;
    grid-row: auto !important;
    width: 100% !important;
  }

  body .lesson-studio .model-card {
    grid-template-rows: auto auto auto auto auto !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    height: auto !important;
    max-height: none !important;
    min-height: 0 !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-inspector,
  body .learning-flow.course-flow.lesson-studio .lesson-inspector,
  body .lesson-studio .lesson-mistake-panel,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel,
  body .lesson-studio .lesson-practice,
  body .learning-flow.course-flow.lesson-studio .lesson-practice {
    grid-template-columns: minmax(0, 1fr) !important;
    grid-template-rows: auto !important;
  }
}

@media (max-width: 720px) {
  body .lesson-studio .visual-stage .equation-responsive-board,
  body .learning-flow.course-flow.lesson-studio .visual-stage .equation-responsive-board {
    box-sizing: border-box !important;
    padding-top: 6px !important;
    grid-template-rows: 32px minmax(0, 1fr) !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel,
  body .learning-flow.course-flow.lesson-studio .visual-stage .balance-step-panel {
    align-self: start !important;
  }

  body .lesson-studio .visual-stage .balance-step-panel button,
  body .learning-flow.course-flow.lesson-studio .visual-stage .balance-step-panel button {
    min-height: 30px !important;
    height: 30px !important;
    line-height: 1 !important;
  }

  body .lesson-studio .visual-stage .mobile-equation-balance,
  body .learning-flow.course-flow.lesson-studio .visual-stage .mobile-equation-balance {
    height: 246px !important;
  }
}

/* G7 strict-qa1: final safety layer for visible text and stage bounds. */
body .lesson-studio .formula-strip,
body .learning-flow.course-flow.lesson-studio .formula-strip {
  box-sizing: border-box !important;
  min-height: 40px !important;
  height: auto !important;
  max-height: none !important;
  padding: 5px 8px !important;
  align-items: center !important;
  gap: 6px !important;
  overflow: visible !important;
}

body .lesson-studio .formula-pill,
body .learning-flow.course-flow.lesson-studio .formula-pill {
  box-sizing: border-box !important;
  min-height: 28px !important;
  height: auto !important;
  max-height: none !important;
  padding: 5px 8px !important;
  line-height: 1.15 !important;
  white-space: normal !important;
  overflow: visible !important;
  text-overflow: clip !important;
}

body .lesson-studio .model-card,
body .learning-flow.course-flow.lesson-studio .model-card {
  grid-template-rows: 54px auto 28px minmax(0, 246px) 32px !important;
}

body .lesson-studio .visual-stage,
body .learning-flow.course-flow.lesson-studio .visual-stage {
  box-sizing: border-box !important;
}

body .lesson-studio .visual-stage:has(.function-lab),
body .learning-flow.course-flow.lesson-studio .visual-stage:has(.function-lab) {
  padding: 6px !important;
}

body .lesson-studio .visual-stage .function-lab,
body .learning-flow.course-flow.lesson-studio .visual-stage .function-lab {
  box-sizing: border-box !important;
  width: 100% !important;
  max-width: 100% !important;
  min-width: 0 !important;
  padding: 8px !important;
  gap: 8px !important;
  grid-template-columns: minmax(154px, .72fr) minmax(260px, 1.22fr) minmax(132px, .56fr) !important;
}

body .lesson-studio .visual-stage .function-lab section,
body .learning-flow.course-flow.lesson-studio .visual-stage .function-lab section,
body .lesson-studio .visual-stage .function-table-panel,
body .learning-flow.course-flow.lesson-studio .visual-stage .function-table-panel {
  box-sizing: border-box !important;
  min-width: 0 !important;
  max-width: 100% !important;
}

body .lesson-studio .visual-stage .function-table-panel,
body .learning-flow.course-flow.lesson-studio .visual-stage .function-table-panel {
  padding: 8px !important;
  gap: 4px !important;
}

@media (min-width: 1181px) {
  body .lesson-studio .formula-strip,
  body .learning-flow.course-flow.lesson-studio .formula-strip {
    min-height: 40px !important;
  }

  body .lesson-studio .visual-stage:has(.function-lab),
  body .learning-flow.course-flow.lesson-studio .visual-stage:has(.function-lab) {
    height: 246px !important;
    max-height: 246px !important;
    overflow: hidden !important;
  }
}

@media (max-width: 760px) {
  body .lesson-studio .formula-strip,
  body .learning-flow.course-flow.lesson-studio .formula-strip {
    width: 100% !important;
    max-width: 100% !important;
    min-height: 42px !important;
    margin-left: 0 !important;
    margin-right: 0 !important;
  }
}

/* G7 strict-qa2: give the desktop learning card enough real height after text is un-clipped. */
@media (min-width: 1181px) {
  body .learning-flow.course-flow.lesson-studio,
  body .lesson-studio {
    grid-template-rows: 560px 210px auto !important;
  }

  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main {
    min-height: 560px !important;
    max-height: none !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    min-height: 500px !important;
    height: 500px !important;
    max-height: 500px !important;
    grid-template-rows: 54px auto 28px minmax(0, 286px) 32px !important;
    overflow: hidden !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    min-height: 286px !important;
    height: 286px !important;
    max-height: 286px !important;
  }

  body .lesson-studio .visual-stage:has(.function-lab),
  body .learning-flow.course-flow.lesson-studio .visual-stage:has(.function-lab) {
    height: 286px !important;
    max-height: 286px !important;
  }
}

/* G7 strict-qa3: restore the function lab to one column on phones after the final desktop guard. */
@media (max-width: 900px) {
  body .lesson-studio .visual-stage:has(.function-lab),
  body .learning-flow.course-flow.lesson-studio .visual-stage:has(.function-lab) {
    height: auto !important;
    min-height: 820px !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-studio .visual-stage .function-lab,
  body .learning-flow.course-flow.lesson-studio .visual-stage .function-lab {
    grid-template-columns: minmax(0, 1fr) !important;
    grid-template-rows: auto auto auto !important;
    width: 100% !important;
    max-width: 100% !important;
  }

  body .lesson-studio .visual-stage .function-graph-panel,
  body .learning-flow.course-flow.lesson-studio .visual-stage .function-graph-panel,
  body .lesson-studio .visual-stage .function-machine-graph,
  body .learning-flow.course-flow.lesson-studio .visual-stage .function-machine-graph {
    width: 100% !important;
    max-width: 100% !important;
  }
}

/* Real-QA-20260729: fix confirmed global clipping/overlap issues from QA and strict G7 audit. */
@media (min-width: 1181px) {
  body .learning-flow.course-flow.lesson-studio,
  body .lesson-studio {
    grid-template-rows: auto auto auto !important;
    align-items: start !important;
  }

  body .lesson-studio .lesson-main,
  body .learning-flow.course-flow.lesson-studio .lesson-main {
    min-height: 0 !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    min-height: 0 !important;
    height: auto !important;
    max-height: none !important;
    grid-template-rows: auto auto auto auto auto !important;
    overflow: visible !important;
  }

  body .lesson-studio .visual-stage,
  body .learning-flow.course-flow.lesson-studio .visual-stage {
    min-height: 372px !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-studio .visual-stage:has(.function-lab),
  body .learning-flow.course-flow.lesson-studio .visual-stage:has(.function-lab) {
    min-height: 372px !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-studio .visual-stage .function-lab,
  body .learning-flow.course-flow.lesson-studio .visual-stage .function-lab {
    min-height: 342px !important;
  }

  body .lesson-inspector,
  body .lesson-studio .lesson-inspector {
    grid-template-rows: auto auto auto !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-inspector .mini-card,
  body .lesson-studio .lesson-inspector .mini-card {
    min-height: 0 !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-inspector .lesson-target-card h3,
  body .lesson-inspector .problem-card h3,
  body .lesson-inspector .target-evidence span,
  body .lesson-inspector #solve li {
    display: block !important;
    -webkit-line-clamp: unset !important;
    -webkit-box-orient: unset !important;
    white-space: normal !important;
    overflow: visible !important;
    text-overflow: clip !important;
  }

  body .lesson-inspector .target-evidence {
    grid-template-columns: minmax(0, 1fr) !important;
  }

  body .lesson-inspector .target-evidence span {
    min-height: 28px !important;
    padding: 6px 8px !important;
    line-height: 1.2 !important;
    text-align: center !important;
  }

  body .lesson-studio .lesson-mistake-panel,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel {
    display: grid !important;
    grid-template-rows: auto auto auto auto !important;
    height: auto !important;
    max-height: none !important;
    gap: 10px !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-mistake-panel .mini-card,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel .mini-card,
  body .lesson-studio .lesson-mistake-panel .explanation-card,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel .explanation-card {
    min-height: 0 !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }

  body .lesson-studio .lesson-mistake-panel .explanation-card label,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel .explanation-card label,
  body .lesson-studio .lesson-mistake-panel .explanation-feedback,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel .explanation-feedback {
    white-space: normal !important;
    overflow: visible !important;
    text-overflow: clip !important;
    line-height: 1.25 !important;
  }

  body .lesson-studio .lesson-mistake-panel .complete-button,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel .complete-button {
    position: static !important;
    min-height: 46px !important;
    margin: 0 !important;
    z-index: auto !important;
  }

  body .lesson-studio .lesson-mistake-panel .completion-evidence,
  body .learning-flow.course-flow.lesson-studio .lesson-mistake-panel .completion-evidence {
    min-height: 0 !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }
}

@media (max-width: 760px) {
  body .lesson-studio .model-card,
  body .learning-flow.course-flow.lesson-studio .model-card {
    display: grid !important;
    grid-template-rows: auto auto auto auto auto !important;
    gap: 8px !important;
    overflow: visible !important;
  }

  body .lesson-studio .formula-strip,
  body .learning-flow.course-flow.lesson-studio .formula-strip,
  body .lesson-studio .model-feedback,
  body .learning-flow.course-flow.lesson-studio .model-feedback {
    position: static !important;
    z-index: auto !important;
    margin: 0 8px !important;
  }

  body .lesson-studio .model-feedback,
  body .learning-flow.course-flow.lesson-studio .model-feedback {
    min-height: 0 !important;
    height: auto !important;
    max-height: none !important;
    overflow: visible !important;
  }
}

/* Balance visual pass: Guizang-inspired material teaching objects with short automatic demonstrations. */
.material-balance-demo,
.material-equation-balance-svg {
  overflow: visible;
}

.material-balance-demo text,
.material-equation-balance-svg text {
  letter-spacing: 0;
}

.equality-demo-beam {
  transform-box: fill-box;
  transform-origin: center;
  animation: equalityBeamSettle 4200ms cubic-bezier(.2, .8, .2, 1) both;
}

.equality-remove-left,
.equality-remove-right {
  transform-box: fill-box;
  transform-origin: center;
  animation: equalityTakeAway 4200ms cubic-bezier(.22, .9, .16, 1) both;
}

.equality-remove-right {
  animation-delay: 80ms;
}

.equality-demo-arrows {
  animation: equalityArrowCue 4200ms ease both;
}

.equality-left-load rect,
.equality-right-load rect,
.material-equation-balance-svg .balance-x-tile rect,
.material-equation-balance-svg .balance-unit-tile rect,
.material-equation-balance-svg .balance-result-group rect {
  vector-effect: non-scaling-stroke;
}

.material-equation-balance {
  border-radius: 24px;
}

.material-equation-balance-svg > rect:first-of-type {
  filter: drop-shadow(0 18px 34px rgba(45, 82, 98, .075));
}

.material-equation-balance-svg [stroke="#17384a"] {
  stroke: rgba(23, 48, 71, .78);
}

.material-equation-balance-svg .balance-auto-demo {
  animation: balanceAutoCue 4600ms ease both;
  pointer-events: none;
}

.material-equation-balance-svg .balance-auto-demo path {
  stroke-dasharray: 90;
  stroke-dashoffset: 90;
  animation: balanceArrowDraw 4600ms ease both;
}

.material-equation-balance-svg .balance-auto-demo rect {
  animation: balanceCuePlate 4600ms ease both;
}

.material-equation-balance-svg .balance-auto-demo text {
  animation: balanceCueText 4600ms ease both;
}

.material-equation-balance-svg .balance-x-tile,
.material-equation-balance-svg .balance-unit-tile,
.material-equation-balance-svg .balance-result-group {
  filter: drop-shadow(0 8px 12px rgba(35, 71, 112, .12));
}

.material-equation-balance-svg .balance-pan-labels rect {
  backdrop-filter: blur(12px);
}

@keyframes equalityBeamSettle {
  0%, 16% {
    transform: rotate(-2deg);
  }
  38%, 100% {
    transform: rotate(0deg);
  }
}

@keyframes equalityTakeAway {
  0%, 16% {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
  46%, 62% {
    opacity: .96;
    transform: translateY(-48px) scale(.94);
  }
  82%, 100% {
    opacity: .16;
    transform: translateY(-74px) scale(.82);
  }
}

@keyframes equalityArrowCue {
  0%, 10% {
    opacity: 0;
    transform: translateY(8px);
  }
  24%, 68% {
    opacity: 1;
    transform: translateY(0);
  }
  100% {
    opacity: .42;
  }
}

@keyframes balanceAutoCue {
  0%, 10% {
    opacity: 0;
    transform: translateY(10px);
  }
  22%, 68% {
    opacity: 1;
    transform: translateY(0);
  }
  100% {
    opacity: .18;
    transform: translateY(-4px);
  }
}

@keyframes balanceArrowDraw {
  0%, 18% {
    stroke-dashoffset: 90;
  }
  48%, 100% {
    stroke-dashoffset: 0;
  }
}

@keyframes balanceCuePlate {
  0%, 16% {
    transform: scale(.94);
  }
  30%, 60% {
    transform: scale(1);
  }
  100% {
    transform: scale(.98);
  }
}

@keyframes balanceCueText {
  0%, 14% {
    opacity: 0;
  }
  28%, 72% {
    opacity: 1;
  }
  100% {
    opacity: .55;
  }
}

@media (prefers-reduced-motion: reduce) {
  .equality-demo-beam,
  .equality-remove-left,
  .equality-remove-right,
  .equality-demo-arrows,
  .material-equation-balance-svg .balance-auto-demo,
  .material-equation-balance-svg .balance-auto-demo path,
  .material-equation-balance-svg .balance-auto-demo rect,
  .material-equation-balance-svg .balance-auto-demo text {
    animation: none !important;
  }
}

@media (max-width: 760px) {
  .mobile-equation-balance {
    background:
      radial-gradient(circle at 50% 0%, rgba(255, 255, 255, .96), transparent 44%),
      linear-gradient(180deg, rgba(246, 252, 255, .96), rgba(238, 248, 244, .9)) !important;
    border: 1px solid rgba(69, 102, 116, .14) !important;
    box-shadow: 0 18px 36px rgba(45, 82, 98, .08) !important;
  }

  .mobile-pan {
    background: rgba(255, 255, 255, .72) !important;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, .92), 0 10px 22px rgba(45, 82, 98, .06) !important;
  }
}