.learning-tools { margin: 1.25rem 0; border-block: 1px solid var(--rule); }
.learning-tools [hidden], .learning-library [hidden], .learning-action[hidden] { display: none !important; }
.learning-tools > summary, .learning-library > details > summary { padding: 1rem 0; cursor: pointer; font-weight: 600; font-size: 1.05rem; }
.learning-tools-body { padding: 0 0 1.5rem; max-width: 72ch; }
.learning-library { padding-block: 2.5rem; border-block: 1px solid var(--rule); }
.learning-library > h2 { margin-top: 0; }
.learning-library > details { border-bottom: 1px solid var(--rule); }
.learning-library > details > div, .learning-library > details > p { max-width: 72ch; }
.learning-entry { padding-block: 1.25rem; border-top: 1px solid var(--rule); overflow-wrap: anywhere; }
.learning-entry h3 { font-family: var(--sans); font-size: 1.2rem; font-weight: 600; margin: 0 0 .4rem; }
.learning-entry p { margin-block: .5rem; }
.learning-entry-actions { display: flex; flex-wrap: wrap; align-items: center; gap: .7rem 1.25rem; margin-block: .75rem; }
.learning-action { border: 0; padding: .35rem 0; min-height: 44px; background: none; font: inherit; color: var(--terracotta-text); text-decoration: underline; text-underline-offset: .2em; cursor: pointer; }
.learning-action:hover { color: var(--ink); }
.learning-action:disabled { opacity: .6; cursor: default; }
.learning-help { color: var(--ink-soft); font-size: 1rem; line-height: 1.6; }
.learning-note-editor { display: grid; gap: .85rem; margin-top: 1.5rem; }
.learning-note-editor label { display: grid; gap: .35rem; font-weight: 500; }
.learning-note-editor input, .learning-note-editor select, .learning-note-editor textarea { box-sizing: border-box; width: 100%; min-width: 0; padding: .75rem; border: 1px solid var(--paper-edge); border-radius: 4px; background: var(--paper); color: var(--ink); font: inherit; font-size: 1.05rem; caret-color: var(--terracotta-text); }
.learning-note-editor textarea { resize: vertical; }
.learning-note-text { white-space: pre-wrap; }
.learning-conflict { padding: 1rem 0; border-block: 1px solid var(--terracotta-text); }
.learning-conflict pre { white-space: pre-wrap; overflow-wrap: anywhere; font: inherit; background: var(--paper-deep); padding: 1rem; }
.learning-action:focus-visible, .learning-tools summary:focus-visible, .learning-library summary:focus-visible { outline: 2px solid var(--terracotta-text); outline-offset: 3px; }
.learning-quiz-save { font-size: 1rem; color: var(--ink-soft); margin-block: .7rem; }
.learning-note-editor > h3, .notebook-list-title { font: 600 1.1rem var(--sans); margin: 0; }
.notebook-storage { margin-top: 1.5rem; border-top: 1px solid var(--rule); }
.notebook-storage > summary { padding-block: 1rem; cursor: pointer; font-weight: 500; }
.learning-notebook { margin: 0; border: 0; }
.notebook-launch { position: fixed; z-index: 40; right: max(1rem, env(safe-area-inset-right)); bottom: max(1rem, env(safe-area-inset-bottom)); font-size: 1rem; letter-spacing: 0; padding: .75rem 1.4rem; }
.notebook-panel { position: fixed; z-index: 50; inset: 1rem 1rem 1rem auto; width: min(27rem, calc(100vw - 2rem)); max-height: calc(100dvh - 2rem); display: flex; flex-direction: column; background: var(--paper); border: 1px solid var(--rule-strong); border-radius: 4px; color: var(--ink); font: 400 1rem/1.5 var(--sans); }
.notebook-heading { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: .65rem 1.25rem; border-bottom: 1px solid var(--rule); flex-shrink: 0; }
.notebook-heading h2 { font: 600 1.2rem var(--sans); margin: 0; }
.notebook-scroll { min-height: 0; overflow-y: auto; overscroll-behavior: contain; scrollbar-color: var(--ink-soft) var(--paper-deep); padding: 1rem 1.25rem; }
.notebook-context { margin: 0 0 1.2rem; color: var(--ink-soft); }
.notebook-panel .learning-tools-body { padding-bottom: 0; }
.notebook-panel .learning-entry { padding-block: .85rem; }
.notebook-panel .learning-entry h3 { font-size: 1.05rem; }
.notebook-panel .learning-note-text { line-height: 1.6; }
.notebook-panel .learning-entry-actions { gap: .35rem 1rem; }
.notebook-panel .learning-help { font-size: .95rem; }
.notebook-panel .btn { font-size: 1rem; letter-spacing: 0; padding: .65rem 1rem; }
.notebook-panel .learning-entry[data-current-section] { background: var(--paper-deep); padding-inline: .75rem; }
.notebook-launch:focus-visible, .notebook-panel :focus-visible, .notebook-storage > summary:focus-visible { outline: 2px solid var(--terracotta-text); outline-offset: 3px; }
/* A reserved reading rail, not an overlay, when both columns have room. */
@media screen and (min-width: 1200px) {
  .notebook-docked { --notebook-rail-width: clamp(24rem, 30vw, 27rem); --notebook-rail-gap: 1.5rem; }
  .notebook-docked .page-shell { padding-inline-end: calc(var(--gutter) + var(--notebook-rail-width) + var(--notebook-rail-gap)); }
  .notebook-docked .notebook-panel { right: max(var(--gutter), calc((100vw - 1440px) / 2 + var(--gutter))); width: var(--notebook-rail-width); }
  .notebook-docked #main-content { min-width: 0; container: notebook-lesson / inline-size; }
  .notebook-docked .site-header { flex-wrap: wrap; gap: .75rem 1.5rem; padding-block: 1rem; }
  .notebook-docked .brand-division { display: none; }
  .notebook-docked .site-footer { flex-wrap: wrap; }
}
/* Viewport media rules cannot see the narrower lesson beside the dock. */
@container notebook-lesson (max-width: 900px) {
  .notebook-docked :is(.chapter-hero-grid, .opening-case, .living-update, .learning-loop, .rhythm-console,
  .atlas-session, .aad-compendium-head, .aad-decision-frame, .mechanism-note,
  .reading-routes, .trial-figures, .figure-debrief > div, .ci-forest) { grid-template-columns: 1fr; }
  .notebook-docked .chapter-routes { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .notebook-docked .chapter-routes-intro { grid-column: 1 / -1; }
  .notebook-docked .case-label { min-height: 0; flex-direction: row; padding-bottom: 1rem; border-right: 0; border-bottom: 1px solid currentColor; }
  .notebook-docked .rhythm-screen { border-right: 0; border-bottom: 1px solid rgba(236, 228, 210, .13); }
  .notebook-docked :is(.drug-strip, .lens-audit-grid, .aad-mechanism-grid, .media-shelf, .evidence-model) { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .notebook-docked .evidence-model aside { grid-column: 1 / -1; }
  .notebook-docked :is(.atlas-index-head, .lab-heading, .figure-lab-heading) { flex-direction: column; align-items: flex-start; }
  .notebook-docked .atlas-drug-picker { flex-basis: auto; width: 100%; max-width: 460px; }
  .notebook-docked .drug-card > summary { grid-template-columns: auto minmax(0, 1fr) auto; }
  .notebook-docked .drug-tagline { grid-column: 2; grid-row: 2; }
  .notebook-docked :is(.drug-grid, .drug-lenses, .drug-foot) { grid-template-columns: 1fr; }
  .notebook-docked .drug-dosing { padding-left: 0; border-left: 0; padding-top: 1rem; border-top: 1px solid var(--rule); }
  .notebook-docked .atlas-session { gap: 1.5rem; }
}
@container notebook-lesson (max-width: 760px) {
  .notebook-docked .chapter-section-map > .chapter-nav { display: none; }
  .notebook-docked .chapter-contents-mobile { display: block; border-block: 1px solid var(--rule); }
  .notebook-docked .chapter-contents-mobile .chapter-nav { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); margin: 0; padding: .25rem 0 .65rem; border: 0; gap: .15rem .75rem; }
  .notebook-docked .chapter-contents-mobile .chapter-nav a { min-width: 0; font-size: .85rem; }
  .notebook-docked .chapter-shell :is(section[id], article[id], h2[id], h3[id]) { scroll-margin-top: 64px; }
  .notebook-docked :is(.chapter-routes, .decision-split, .rhythm-matrix, .lens-panel, .lens-panel ol,
  .drug-strip, .lens-audit-grid, .aad-mechanism-grid, .media-shelf, .reading-sequence,
  .usedep-ends, .aad-teach-back > div, .excerpt-evidence-grid, .claim-boundary,
  .source-body dl, .progress-sync, .clinical-boundary) { grid-template-columns: 1fr; }
  .notebook-docked :is(.lens-tabs, .rhythm-meta) { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .notebook-docked .lens-callout { padding-right: 0; padding-bottom: 1rem; border-right: 0; border-bottom: 1px solid var(--rule); }
  .notebook-docked .lens-panel li { min-height: 0; }
  .notebook-docked .lens-tabs button:nth-child(2) { border-right: 0; }
  .notebook-docked .lens-tabs button:nth-child(-n + 2) { border-bottom: 1px solid var(--rule); }
  .notebook-docked :is(.decision-node, .root-node) { grid-template-columns: auto 1fr; border-radius: var(--radius); }
  .notebook-docked .decision-node small { grid-column: 1 / -1; }
  .notebook-docked :is(.assessment-item, .atlas-q) { grid-template-columns: 1fr; gap: .6rem; }
  .notebook-docked :is(.item-rationale, .atlas-q-rationale) { grid-column: 1; }
  .notebook-docked .assessment-pager { grid-template-columns: 1fr 1fr; }
  .notebook-docked .assessment-pager > span { grid-column: 1 / -1; grid-row: 1; }
  .notebook-docked .assessment-pager :is([data-assessment-prev], [data-assessment-next]) { grid-row: 2; }
  .notebook-docked :is(.assessment-submit, .source-register-head, .media-library-heading) { flex-direction: column; align-items: flex-start; }
  .notebook-docked .excerpt-footer { grid-template-columns: 1fr; justify-items: start; }
  .notebook-docked .progress-sync-actions { justify-content: flex-start; }
  .notebook-docked .reading-sequence li { min-height: 0; border-right: 0; border-bottom: 1px solid var(--rule); }
}
@media (max-width: 600px) {
  .notebook-panel { inset: auto 0 0; width: 100%; max-height: 88dvh; border-radius: 4px 4px 0 0; box-sizing: border-box; }
  .notebook-scroll { padding-bottom: max(1.25rem, env(safe-area-inset-bottom)); }
}
@media print { .learning-tools, .learning-library, .learning-quiz-save { display: none !important; } }