@media (max-width: 1023px) {
  :root { --rail-w: 78px; }
  .brand { justify-content: center; }
  .brand-type, .nav-link > span:last-child, .rail-footer { display: none; }
  .nav-link { grid-template-columns: 1fr; justify-items: center; padding: 4px; }
  .lesson-shell { grid-template-columns: 1fr; }
  .lesson-toc { display: none; }
}

@media (max-width: 767px) {
  :root { --header-h: 62px; }
  body { padding-bottom: calc(var(--mobile-nav-h) + env(safe-area-inset-bottom)); }
  .app-shell { display: block; }
  .side-rail { display: none; }
  .context-header { padding-left: var(--page-gutter); padding-right: var(--page-gutter); }
  .context-copy strong { max-width: 38vw; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }
  .header-actions { gap: 5px; }
  .profile-pill { width: 44px; padding: 0; justify-content: center; }
  .profile-pill #profileLabel { display: none; }
  .mobile-nav { position: fixed; z-index: 50; left: 0; right: 0; bottom: 0; min-height: calc(var(--mobile-nav-h) + env(safe-area-inset-bottom)); padding: 6px max(8px, env(safe-area-inset-right)) env(safe-area-inset-bottom) max(8px, env(safe-area-inset-left)); display: grid; grid-template-columns: repeat(5,1fr); gap: 2px; border-top: 1px solid var(--line); background: color-mix(in srgb, var(--bg-elevated) 94%, transparent); backdrop-filter: blur(18px); }
  .mobile-nav a { min-height: 54px; display: grid; place-items: center; align-content: center; gap: 3px; color: var(--text-3); border-radius: var(--radius-s); }
  .mobile-nav a.active { color: var(--text); background: var(--surface-2); }
  .mobile-nav span { font: 700 13px/1 var(--font-mono); }
  .mobile-nav small { font-size: 10px; font-weight: 650; }
  .site-footer { display: grid; padding-bottom: 28px; }
  .toast-region { bottom: calc(var(--mobile-nav-h) + env(safe-area-inset-bottom) + 12px); left: 16px; right: 16px; }
  .toast { max-width: none; }
  .dialog-root { padding: 0; align-items: end; }
  .dialog-panel { width: 100%; max-height: calc(100dvh - 16px); border-radius: 22px 22px 0 0; padding-bottom: calc(24px + env(safe-area-inset-bottom)); }
  .lab-workspace { grid-template-columns: 1fr; }
  .lab-controls { border-right: 0; border-bottom: 1px solid var(--line); }
}

@media (max-width: 420px) {
  .context-kicker { display: none; }
  .context-copy strong { max-width: 25vw; font-size: 13px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
}

@media (max-width: 900px) {
  .home-hero { grid-template-columns: 1fr; min-height: auto; padding: 54px 0; }
  .home-hero__system { min-height: 240px; border-left: 0; border-top: 1px solid var(--line); }
  .course-block { grid-template-columns: 1fr; }
  .course-block__header { padding: 26px 0 12px; flex-direction: row; justify-content: space-between; }
  .course-class-list { border-left: 0; }
}
@media (max-width: 650px) {
  .home-grid { grid-template-columns: 1fr; }
  .dashboard-panel { border-right: 0; min-height: auto; }
  .course-card { grid-template-columns: 48px minmax(0,1fr); gap: 12px; padding: 20px 0; }
  .course-card__arrow { display: none; }
  .course-card__top { align-items: flex-start; }
  .lesson-hero { min-height: 320px; }
  .lesson-card-grid { grid-template-columns: 1fr; }
  .comparison-table { margin-inline: calc(var(--page-gutter) * -1); border-left: 0; border-right: 0; }
  .activity-rubric-row { grid-template-columns: 1fr 54px; }
  .activity-rubric-row input { grid-column: 1 / -1; grid-row: 2; }
  .external-mission__head { display: grid; }
  .anonymous-banner { margin-inline: calc(var(--page-gutter) * -1); }
}
@media (max-width: 720px) {
  .project-overview { grid-template-columns: 1fr; gap: 12px; }
  .project-form-grid { grid-template-columns: 1fr; }
  .project-form-grid .field:nth-child(3n) { grid-column: auto; }
  .project-stage__head { grid-template-columns: 1fr; }
}
@media (max-width: 620px) {
  .character-scene-controls { grid-template-columns: 1fr; }
  .video-timeline { grid-template-columns: 1fr; }
  .video-timeline > i { width: 1px; height: 20px; justify-self: center; }
}
@media (max-width: 700px) {
  .labs-grid, .skill-grid, .achievement-grid { grid-template-columns: 1fr; }
  .lab-card { grid-template-columns: 52px 1fr; min-height: 220px; border-right: 0; padding-inline: 0; }
  .lab-card__glyph { width: 48px; height: 48px; }
  .progress-summary { grid-template-columns: repeat(2,1fr); }
  .progress-summary article:nth-child(2) { border-right: 0; }
  .progress-summary article:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .history-list > div { grid-template-columns: 1fr auto; }
  .history-list small { grid-column: 1 / -1; }
}
@media (max-width: 760px) {
  .settings-grid, .tool-grid { grid-template-columns: 1fr; }
  .source-note-grid { grid-template-columns: 1fr; }
  .source-note-grid article { border-right: 0; border-bottom: 1px solid var(--line); }
  .glossary-list { columns: 1; }
  .tool-card footer { display: grid; }
}
@media (max-width: 480px) {
  .inline-create { grid-template-columns: 1fr; }
  .profile-row { align-items: flex-start; flex-direction: column; }
}
@media (max-width: 1023px) {
  .lesson-shell { grid-template-columns: minmax(0,1fr); }
}