/* Ch 5 light-clock: scoped under [data-chapter="light-clock"], §4.1 tokens only. */
[data-chapter="light-clock"] .lc-faint { opacity: .45; }
[data-chapter="light-clock"] .lc-dash { stroke-dasharray: 5 5; }
[data-chapter="light-clock"] .lc-thick { stroke-width: 2.5; }
[data-chapter="light-clock"] .lc-paint { fill: none; stroke-width: 6; stroke-linecap: round; }
[data-chapter="light-clock"] .lc-paint-lab { stroke: var(--c-lab); }
[data-chapter="light-clock"] .lc-paint-rkt { stroke: var(--c-rocket); }
[data-chapter="light-clock"] .lc-hook-art figcaption { text-align: center; }
[data-chapter="light-clock"] .lc-gamma { font-family: var(--font-serif); font-style: italic; font-size: 1.12em; }
[data-chapter="light-clock"] svg .lc-halo { stroke-width: 5px; }
[data-chapter="light-clock"] .lc-friendly { margin: var(--s-5) auto; font-family: var(--font-sans); font-size: .85rem; font-variant-numeric: tabular-nums; border-collapse: collapse; }
[data-chapter="light-clock"] .lc-friendly :is(th, td) { padding: var(--s-1) var(--s-4); text-align: center; border-bottom: 1px solid var(--rule); white-space: nowrap; }
[data-chapter="light-clock"] .lc-friendly thead th { color: var(--ink-muted); }
[data-chapter="light-clock"] .lc-friendly :is(tbody th, td:last-child) { font-weight: 600; }
[data-chapter="light-clock"] .lc-steps { margin: var(--s-3) 0 0; padding-left: 1.4em; }
[data-chapter="light-clock"] .callout.try .lc-done { margin-left: auto; font-size: .7rem; }
[data-chapter="light-clock"] .callout.try.is-done .callout-title { display: flex; align-items: center; gap: .5em; }
/* reserve lab heights (measured after mount, 2026-10-06) so mounting never shifts the page */
[data-chapter="light-clock"] #lab-light-clock-1 .lab-stage { min-height: 660px; }
[data-chapter="light-clock"] #lab-light-clock-2 .lab-stage { min-height: 690px; }
[data-chapter="light-clock"] #lab-light-clock-3 .lab-stage { min-height: 830px; }
[data-chapter="light-clock"] #lab-light-clock-4 .lab-stage { min-height: 680px; }
@media (max-width: 899px) {
  [data-chapter="light-clock"] #lab-light-clock-1 .lab-stage { min-height: 720px; }
  [data-chapter="light-clock"] #lab-light-clock-2 .lab-stage { min-height: 650px; }
  [data-chapter="light-clock"] #lab-light-clock-4 .lab-stage { min-height: 600px; }
}
@media (max-width: 779px) {
  [data-chapter="light-clock"] #lab-light-clock-1 .lab-stage { min-height: 1030px; }
  [data-chapter="light-clock"] #lab-light-clock-2 .lab-stage { min-height: 1250px; }
}
@media (max-width: 599px) {
  [data-chapter="light-clock"] #lab-light-clock-1 .lab-stage { min-height: 1200px; }
  [data-chapter="light-clock"] #lab-light-clock-2 .lab-stage { min-height: 960px; }
  [data-chapter="light-clock"] #lab-light-clock-3 .lab-stage { min-height: 940px; }
  [data-chapter="light-clock"] #lab-light-clock-4 .lab-stage { min-height: 1100px; }
}
/* passing meter sticks */
[data-chapter="light-clock"] :is(.lc-sticks-stage, .lc-dial-panel) { border: 1px solid var(--rule); border-radius: var(--r-m); background: var(--surface); }
[data-chapter="light-clock"] .lc-sticks-stage { margin-top: var(--s-3); overflow: hidden; }
[data-chapter="light-clock"] :is(.lc-sticks-svg, .lc-dial-svg) { display: block; width: 100%; height: auto; font-family: var(--font-sans); }
[data-chapter="light-clock"] .lc-sticks-svg { max-height: 340px; }
[data-chapter="light-clock"] .lc-sticks-svg .lc-frame-title { font-size: 15px; font-weight: 600; }
[data-chapter="light-clock"] .lc-sticks-controls { display: flex; flex-wrap: wrap; align-items: flex-end; gap: var(--s-3) var(--s-5); margin-top: var(--s-4); }
[data-chapter="light-clock"] .lc-sticks-controls .btn { min-height: 44px; }
[data-chapter="light-clock"] .lc-sticks-ledger { margin-top: var(--s-4); }
[data-chapter="light-clock"] .lc-ledger-hyp { margin: 0 0 var(--s-2); font-weight: 600; }
[data-chapter="light-clock"] .lc-ledger { width: 100%; font-variant-numeric: tabular-nums; }
[data-chapter="light-clock"] .lc-ledger .lc-pending { color: var(--ink-muted); font-style: italic; }
[data-chapter="light-clock"] .lc-score { list-style: none; margin: var(--s-3) 0 0; padding: 0; display: flex; flex-wrap: wrap; gap: var(--s-2); }
[data-chapter="light-clock"] .lc-score li { font-size: .78rem; padding: 2px var(--s-3); border: 1px solid var(--rule); border-radius: 999px; color: var(--ink-muted); background: var(--surface); }
[data-chapter="light-clock"] .lc-score li.is-bad { color: var(--c-bad); border-color: currentColor; background: var(--tint-bad); }
[data-chapter="light-clock"] .lc-score li.is-good { color: var(--c-ok); border-color: currentColor; background: var(--tint-ok); }
/* stretch-factor dial */
[data-chapter="light-clock"] .lc-dial-panels { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.07fr); gap: var(--s-4); margin-top: var(--s-3); }
[data-chapter="light-clock"] .lc-dial-panel { padding: var(--s-2); min-width: 0; }
[data-chapter="light-clock"] .lc-dial-svg { overflow: visible; }
[data-chapter="light-clock"] .lc-ref-curve { fill: none; stroke: var(--ink); stroke-width: 2.25; stroke-linecap: round; stroke-linejoin: round; }
[data-chapter="light-clock"] .lc-you-curve { stroke-width: 3; stroke-dasharray: 7 4; stroke-linejoin: round; }
[data-chapter="light-clock"] .lc-forbid { fill: var(--tint-bad); }
[data-chapter="light-clock"] .lc-bad-text { fill: var(--c-bad); }
[data-chapter="light-clock"] .lc-chips { display: flex; flex-wrap: wrap; align-items: center; gap: var(--s-2); margin-top: var(--s-3); }
[data-chapter="light-clock"] .lc-chip { min-height: 32px; min-width: 44px; padding: 2px var(--s-3); font-variant-numeric: tabular-nums; border: 1px solid var(--rule); }
[data-chapter="light-clock"] .lc-chip[aria-pressed="true"] { border-color: var(--c-lab); color: var(--c-lab); background: var(--tint-lab); }
@media (max-width: 599px) {
  [data-chapter="light-clock"] .lc-dial-panels { grid-template-columns: minmax(0, 1fr); }
  [data-chapter="light-clock"] .lc-friendly :is(th, td) { padding: var(--s-1) var(--s-2); }
  [data-chapter="light-clock"] .lc-ledger :is(th, td) { padding: var(--s-1) var(--s-2); font-size: .85rem; }
}
/* redesign (docs/redesign/light-clock.md): orientation card, lab key, numbered Try-its */
[data-chapter="light-clock"] .lc-orient { margin: var(--s-6) 0; max-width: 40rem; }
[data-chapter="light-clock"] .lc-orient > :is(p, ol) + :is(p, ol) { margin-top: var(--s-3); }
[data-chapter="light-clock"] :is(.lc-orient, .lc-key) ol { margin: var(--s-3) 0 0; padding-left: 1.5em; }
[data-chapter="light-clock"] :is(.lc-orient, .lc-key) li + li { margin-top: var(--s-2); }
[data-chapter="light-clock"] .lc-orient-note { font-size: .9rem; color: var(--ink-muted); }
[data-chapter="light-clock"] .lc-key { padding: var(--s-4) var(--s-5) var(--s-3); border-bottom: 1px solid var(--rule); font-size: .92rem; }
[data-chapter="light-clock"] .lc-key > summary { font: 700 .78rem var(--font-sans); letter-spacing: .08em; text-transform: uppercase; cursor: pointer; }
@media (min-width: 900px) { [data-chapter="light-clock"] .lc-key ol { columns: 2; column-gap: var(--s-6); } [data-chapter="light-clock"] .lc-key li { break-inside: avoid; } }
[data-chapter="light-clock"] .lc-step-no { font-weight: 600; letter-spacing: 0; text-transform: none; color: var(--ink-muted); }
/* tick diagram (widgets/light-clock-ticks.js) */
[data-chapter="light-clock"] .lc-ticks-main { display: grid; gap: var(--s-4); }
@container (min-width: 700px) { [data-chapter="light-clock"] .lc-ticks-main { grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); align-items: start; } }
[data-chapter="light-clock"] :is(.lc-ticks-stage, .lc-ticks-side) { min-width: 0; }
[data-chapter="light-clock"] .lc-ticks { font-size: .85rem; font-variant-numeric: tabular-nums; border-collapse: collapse; }
[data-chapter="light-clock"] .lc-ticks :is(th, td) { padding: 2px var(--s-2); text-align: right; vertical-align: middle; }
[data-chapter="light-clock"] .lc-ticks thead th { color: var(--ink-muted); font-weight: 600; white-space: normal; vertical-align: bottom; }
[data-chapter="light-clock"] .lc-ticks :is(thead th:first-child, tbody th) { text-align: left; }
[data-chapter="light-clock"] .lc-ticks tbody + tbody { border-top: 2px solid var(--rule); }
[data-chapter="light-clock"] .lc-ticks tr.is-sel { background: var(--surface-2); }
[data-chapter="light-clock"] .lc-ticks tr.is-sel .lc-ticks-pick { border-color: currentColor; }
[data-chapter="light-clock"] .lc-ticks .is-lab .lc-ticks-pick { color: var(--c-lab); }
[data-chapter="light-clock"] .lc-ticks .is-rkt .lc-ticks-pick { color: var(--c-rocket); }
[data-chapter="light-clock"] .lc-ticks-pick { min-height: 44px; padding: 0 var(--s-2); font: inherit; font-weight: 600; white-space: nowrap; background: none; border: 1px solid transparent; border-radius: var(--r-s); cursor: pointer; }
[data-chapter="light-clock"] .lc-ticks-pick:hover { border-color: var(--rule); }
[data-chapter="light-clock"] .lc-ticks-pick:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
[data-chapter="light-clock"] .lc-ticks-status { min-height: 4.2em; }
@media (max-width: 599px) { [data-chapter="light-clock"] .lc-ticks :is(th, td) { padding: 0 var(--s-1); } [data-chapter="light-clock"] .lc-ticks-pick { padding: 0 var(--s-1); } }
/* revision 2 (docs/redesign/light-clock.md, build log 2) */
[data-chapter="light-clock"] .lc-ticks thead th { white-space: nowrap; }
[data-chapter="light-clock"] .lc-ticks td { min-width: 4.5ch; }
[data-chapter="light-clock"] .lc-ticks td.is-veiled { color: var(--ink-muted); }
[data-chapter="light-clock"] .lc-ticks-controls { display: flex; flex-wrap: wrap; align-items: flex-end; gap: var(--s-3) var(--s-5); }
[data-chapter="light-clock"] .lc-inv-btn { min-height: 44px; border: 1px solid var(--rule); }
[data-chapter="light-clock"] .lc-inv-btn[aria-pressed="true"] { border-color: var(--c-inv); color: var(--c-inv); }
@media (max-width: 599px) { [data-chapter="light-clock"] .lc-ticks-status { min-height: 6.5em; } }
[data-chapter="light-clock"] .lc-dial-controls { display: flex; flex-wrap: wrap; align-items: flex-end; gap: var(--s-3); }
[data-chapter="light-clock"] .lc-dial-controls > :first-child { flex: 1 1 14rem; }
[data-chapter="light-clock"] .lc-nudges { display: flex; gap: var(--s-2); }
[data-chapter="light-clock"] .lc-nudge { min-width: 44px; min-height: 44px; font-size: 1.2rem; font-weight: 700; border: 1px solid var(--rule); }
[data-chapter="light-clock"] svg .lc-muted-text { fill: var(--ink-muted); }
[data-chapter="light-clock"] .lc-spoiler.is-veiled { display: none; }
[data-chapter="light-clock"] .lc-story-why { margin: var(--s-3) 0 0; font-size: .92rem; }
[data-chapter="light-clock"] .lc-story-line { display: block; }
[data-chapter="light-clock"] .lc-story-line + .lc-story-line { margin-top: var(--s-2); }
/* reservations re-measured after revision 2 (2026-10-06; the tick lab gained a button row and a taller status) */
[data-chapter="light-clock"] #lab-light-clock-2 .lab-stage { min-height: 700px; }
@media (max-width: 899px) { [data-chapter="light-clock"] #lab-light-clock-2 .lab-stage { min-height: 650px; } [data-chapter="light-clock"] #lab-light-clock-4 .lab-stage { min-height: 640px; } }
@media (max-width: 779px) { [data-chapter="light-clock"] #lab-light-clock-2 .lab-stage { min-height: 1250px; } [data-chapter="light-clock"] #lab-light-clock-4 .lab-stage { min-height: 600px; } }
@media (max-width: 599px) {
  [data-chapter="light-clock"] #lab-light-clock-1 .lab-stage { min-height: 1240px; }
  [data-chapter="light-clock"] #lab-light-clock-2 .lab-stage { min-height: 1050px; }
  [data-chapter="light-clock"] #lab-light-clock-3 .lab-stage { min-height: 970px; }
  [data-chapter="light-clock"] #lab-light-clock-4 .lab-stage { min-height: 1100px; }
}
/* follow-up grade (2026-10-06): fallbacks, sticks rule line and caption row, answer reveal, lab notes, algebra lines */
@media (scripting: enabled) { [data-chapter="light-clock"] figure.lab:not(.mount-failed) .lab-stage > .fallback { display: none; } }
[data-chapter="light-clock"] .lc-nowrap { white-space: nowrap; }
[data-chapter="light-clock"] .lc-alg { margin: var(--s-2) 0; padding-left: 1.6em; list-style: decimal; }
[data-chapter="light-clock"] .lc-alg li + li { margin-top: var(--s-1); }
[data-chapter="light-clock"] .lc-sticks-cap { margin: 0; padding: 0 var(--s-4) var(--s-3); min-height: 3em; font-size: .85rem; text-align: center; }
[data-chapter="light-clock"] .lc-sticks-cap .is-lab { color: var(--c-lab); }
[data-chapter="light-clock"] .lc-sticks-cap .is-rkt { color: var(--c-rocket); }
[data-chapter="light-clock"] .lc-ledger-hyp { padding: var(--s-2) var(--s-3); border: 1px solid var(--rule); border-radius: var(--r-m); background: var(--surface-2); font-weight: 400; }
[data-chapter="light-clock"] .lc-ledger thead small { display: block; font-weight: 400; color: var(--ink-muted); }
[data-chapter="light-clock"] .lc-answer { margin: var(--s-5) 0; padding: var(--s-3) var(--s-4); border: 1px solid var(--rule); border-radius: var(--r-m); }
[data-chapter="light-clock"] .lc-answer > summary { cursor: pointer; font-weight: 700; }
[data-chapter="light-clock"] .lc-answer-note { display: block; font-weight: 400; font-size: .9rem; color: var(--ink-muted); }
[data-chapter="light-clock"] .lc-answer[open] .lc-answer-note { display: none; }
[data-chapter="light-clock"] .lc-answer > p { margin-top: var(--s-3); }
[data-chapter="light-clock"] .lc-lab-note { margin: var(--s-2) 0 0; font-size: .85rem; }
[data-chapter="light-clock"] .lc-lab-note.is-bad { color: var(--c-bad); font-weight: 600; }
[data-chapter="light-clock"] .lc-break-notes { flex-basis: 100%; }
[data-chapter="light-clock"] .lc-break-notes:empty { display: none; }
[data-chapter="light-clock"] .lc-ledger thead th { white-space: normal; }
[data-chapter="light-clock"] .lc-ledger tbody th { white-space: nowrap; }