/* Palette from dfrancour.dev: cool neutrals, purple accent. */
:root {
  --bg: oklch(98% 0.005 220);
  --raised: oklch(99.6% 0.002 220);
  --ink: oklch(18% 0.008 220);
  --muted: oklch(45% 0.018 220);
  --faint: oklch(52% 0.02 220);
  --edge: oklch(90% 0.01 220);
  --hover: oklch(95% 0.008 220);
  --accent: oklch(45% 0.18 310);
  --accent-hover: oklch(50% 0.2 310);
  --accent-ink: oklch(99% 0.004 310);
  --right: oklch(46% 0.12 155);
  --wrong: oklch(54% 0.19 25);

  --plate: #ffffff;
  --plate-rim: oklch(80% 0.01 220);
  --plate-ink: oklch(32% 0.13 265);
  --plate-script: oklch(52% 0.2 25);
  --sticker: oklch(86% 0.15 92);

  --font-ui: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "SF Mono", Menlo, Consolas, monospace;
  --font-plate: "DIN Condensed", "Roboto Condensed", "Arial Narrow", var(--font-ui);
  --radius: 8px;
  color-scheme: light;
}

/* Type sizes, and nothing between: 11 (uppercase labels), 12, 14, 16, 17 (the reader), 20, 24, 28, 48.
   Spacing is in fours: 4, 8, 12, 16, 24, 32, 48. */

@media (prefers-color-scheme: dark) {
  :root {
    --bg: oklch(18% 0.008 220);
    --raised: oklch(22% 0.01 220);
    --ink: oklch(95% 0.008 220);
    --muted: oklch(74% 0.016 220);
    --faint: oklch(64% 0.018 220);
    --edge: oklch(29% 0.014 220);
    --hover: oklch(24% 0.012 220);
    --accent: oklch(72% 0.15 310);
    --accent-hover: oklch(78% 0.14 310);
    --accent-ink: oklch(15% 0.01 310);
    --right: oklch(78% 0.15 155);
    --wrong: oklch(68% 0.17 25);

    --plate: oklch(93% 0.006 220);
    --plate-rim: oklch(70% 0.012 220);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 var(--font-ui);
  -webkit-font-smoothing: antialiased;
}
h1, h2, p { margin: 0; }
h1:focus { outline: none; }
a, button { touch-action: manipulation; -webkit-tap-highlight-color: transparent; }
button { font: inherit; color: inherit; }
button:not(:disabled) { cursor: pointer; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }

.icon {
  width: 18px; height: 18px; flex: none;
  fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round;
}
.figure { font-family: var(--font-mono); font-variant-numeric: tabular-nums; font-weight: 600; }
.eyebrow { color: var(--faint); font-size: 0.75rem; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase; }

/* The page is one column, padded clear of the notch and home indicator. */
main {
  min-height: 100dvh;
  max-width: 34rem;
  margin: 0 auto;
  padding:
    env(safe-area-inset-top)
    max(20px, env(safe-area-inset-right))
    env(safe-area-inset-bottom)
    max(20px, env(safe-area-inset-left));
  display: flex;
  flex-direction: column;
}

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 40px; padding: 8px 16px;
  border: 1px solid var(--edge); border-radius: var(--radius);
  background: var(--raised); color: var(--ink);
  font-weight: 500; text-decoration: none; white-space: nowrap;
  transition: background-color 150ms, border-color 150ms;
}
.btn:active { background: var(--hover); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); font-weight: 600; }
.btn.primary:active { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn.quiet { background: transparent; border-color: transparent; color: var(--muted); }
.btn.quiet:active { background: var(--hover); color: var(--ink); }
.btn.big { min-height: 48px; padding: 12px 24px; font-size: 1.0625rem; }

/* ---------- home ---------- */

.home {
  flex: 1;
  display: grid;
  align-content: center;
  justify-items: center;
  gap: 24px;
  padding-block: 48px;
  text-align: center;
}

/* The wordmark is a California plate (drawn in home.js). */
.plate { width: min(80vw, 340px); margin-bottom: 8px; }
.plate svg { display: block; width: 100%; height: auto; overflow: visible; filter: drop-shadow(0 6px 12px oklch(18% 0.008 220 / 0.14)); }
/* A shadow on a dark page only shows as a smudge. */
@media (prefers-color-scheme: dark) { .plate svg { filter: none; } }
.plate-body { fill: var(--plate); stroke: var(--plate-rim); stroke-width: 1.5; }
.plate-emboss { fill: none; stroke: var(--plate-rim); stroke-width: 1; opacity: 0.6; }
.plate-sticker { fill: var(--sticker); }
.plate-state { fill: var(--plate-script); font: italic 700 25px ui-serif, Georgia, "Times New Roman", serif; }
.plate-text { fill: var(--plate-ink); font: 600 84px var(--font-plate); }

.tagline { color: var(--muted); max-width: 36ch; text-wrap: balance; }
.fine { padding-block: 16px 8px; color: var(--faint); font-size: 0.75rem; text-align: center; }
/* Home and source, quiet as the disclaimer: the favicon and the GitHub mark at text size. */
.fine-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 0 12px; margin-top: 4px; }
.fine-links a {
  display: inline-flex; align-items: center; gap: 6px;
  min-height: 36px; padding-inline: 4px;
  color: inherit; text-decoration: none; transition: color 150ms;
}
.fine-links a:active { color: var(--muted); }
.fine-links img { border-radius: 3px; }
.mark { width: 14px; height: 14px; flex: none; fill: currentColor; }

/* ---------- quiz and results ---------- */

.bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
  color: var(--muted);
  font-size: 0.875rem;
}
/* The handbook's own pages (contents, a section, its questions) keep their path in view, frosted
   as in the reader. Its edge shows once something has scrolled under it. */
.bar.is-pinned {
  position: sticky;
  top: env(safe-area-inset-top);
  z-index: 10;
  margin-inline: calc(50% - 50vw);
  padding-inline: max(20px, calc(50vw - 50%));
  background: color-mix(in oklch, var(--bg) 80%, transparent);
  -webkit-backdrop-filter: blur(16px) saturate(1.4);
  backdrop-filter: blur(16px) saturate(1.4);
  border-bottom: 1px solid transparent;
}
@supports (animation-timeline: scroll()) {
  .bar.is-pinned { animation: bar-edge linear both; animation-timeline: scroll(root); animation-range: 0 24px; }
}
@keyframes bar-edge { to { border-bottom-color: color-mix(in oklch, var(--edge) 70%, transparent); } }
.back {
  display: grid; place-items: center;
  width: 36px; height: 36px; margin-left: -9px;
  border-radius: var(--radius);
  color: var(--muted);
}
.back:active { background: var(--hover); color: var(--ink); }

/* The contents page's "% read", and in its place, asking to start over. */
.bar-end, .bar-ask { display: flex; align-items: center; gap: 4px; }
.bar-end .btn { min-height: 36px; padding: 6px 12px; }
.bar-end > .btn.quiet { gap: 0.3em; margin-right: -12px; font-weight: inherit; }
.bar-end [hidden] { display: none; }

.progress {
  appearance: none;
  display: block;
  width: 100%;
  height: 2px;
  margin: 0 0 32px;
  border: 0;
  background: var(--edge);
}
.progress::-webkit-progress-bar { background: var(--edge); }
.progress::-webkit-progress-value { background: var(--accent); transition: width 200ms; }
.progress::-moz-progress-bar { background: var(--accent); }

.prompt {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
  text-wrap: pretty;
}

.choices { list-style: none; margin: 24px 0 0; padding: 0; border-block: 1px solid var(--edge); }
.choices li + li { border-top: 1px solid var(--edge); }
.choice {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: calc(100% + 24px);
  min-height: 56px;
  margin-inline: -12px;
  padding: 12px;
  border: 0;
  border-radius: var(--radius);
  background: transparent;
  text-align: start;
  transition: background-color 150ms, color 150ms;
}
.choice:not(:disabled):active { background: var(--hover); }
.choice:disabled { cursor: default; }
.choice .icon { width: 20px; height: 20px; }
.choice.is-right { color: var(--right); font-weight: 600; }
.choice.is-wrong { color: var(--wrong); }
.choice.is-other { color: var(--faint); }

/* Brought into view after an answer: clear of Next, stuck along the foot. */
.why { margin-top: 24px; color: var(--muted); scroll-margin-bottom: 104px; }

/* The handbook text an answer rests on, and where it is. */
.source { margin: 16px 0 0; }
.source blockquote {
  margin: 0;
  padding-left: 14px;
  border-left: 2px solid var(--edge);
  color: var(--ink);
}
.source > figcaption { margin-top: 4px; padding-left: 16px; font-size: 0.875rem; }
/* The figure a quote points at ("the table below"), in line with the quote. */
.source .hb-figure, .source .hb-figure.is-small { float: none; margin: 8px 0 0 16px; }
.source a { color: var(--accent); text-decoration: none; }
/* Small links, tall enough to tap: the padding reaches past the line without moving it. */
:is(.source, .credit, .qa-from) a { display: inline-block; padding-block: 9px; margin-block: -9px; }
.source a:active { text-decoration: underline; }
.source .figure { font-size: 0.75rem; }
.rows .source { margin-top: 8px; }
.why strong { font-weight: 600; }
.why .is-right { color: var(--right); }
.why .is-wrong { color: var(--wrong); }

/* Next sits at the foot of the screen, within reach of a thumb. */
.next {
  position: sticky;
  bottom: 0;
  display: flex;
  justify-content: flex-end;
  margin-top: auto;
  padding: 24px 0 max(16px, env(safe-area-inset-bottom));
  background: linear-gradient(transparent, var(--bg) 24px);
}
.next { gap: 8px; }
.next .btn { min-width: 9rem; }

.score { display: flex; align-items: baseline; gap: 16px; font-size: 1rem; font-weight: normal; }
.score .figure { font-size: 3rem; line-height: 1; letter-spacing: -0.04em; }
.score .of { color: var(--faint); }
.verdict { font-weight: 600; }
.verdict.is-right { color: var(--right); }
.verdict.is-wrong { color: var(--wrong); }
.score-note { margin-top: 8px; color: var(--muted); font-size: 0.875rem; }

.missed { margin-top: 48px; }
.missed .eyebrow { margin-bottom: 8px; }
.rows { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--edge); }
.rows > li { display: grid; gap: 4px; padding-block: 16px; border-bottom: 1px solid var(--edge); }
.rows .q { font-weight: 500; }
.rows .a { display: flex; align-items: flex-start; gap: 8px; }
/* On the first line of an answer that wraps: (24px line - 16px icon) / 2. */
.rows .a .icon { width: 16px; height: 16px; margin-top: 4px; }
.rows .a.is-wrong { color: var(--wrong); }
.rows .a.is-right { color: var(--right); }
.rows .note { color: var(--muted); }

/* The sign or signal a question asks about: its own line, never floated beside the text. */
.q-figure { margin-top: 16px; }
.q-figure .hb-figure { margin: 0; float: none; }
.rows .q-figure, .qa-part .q-figure { margin-block: 4px; }

/* ---------- toast ---------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: max(16px, env(safe-area-inset-bottom));
  translate: -50% 0;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 6px 6px 16px;
  border-radius: calc(var(--radius) + 6px);
  background: var(--ink);
  color: var(--bg);
  font-size: 0.875rem;
  width: max-content;
  max-width: calc(100% - 32px);
  box-shadow: 0 8px 16px oklch(18% 0.008 220 / 0.2);
}
@media (prefers-color-scheme: dark) { .toast { box-shadow: none; } }
.toast .btn { flex: none; min-height: 32px; padding: 4px 12px; background: var(--bg); border-color: var(--bg); color: var(--ink); }
/* Dismiss: as quiet as the toast allows, beside its action. */
.toast-close { flex: none; display: grid; place-items: center; width: 32px; height: 32px; margin-left: -4px; padding: 0; border: 0; border-radius: var(--radius); background: none; color: inherit; opacity: 0.7; }
.toast-close .icon { width: 18px; height: 18px; }
.toast-close:active { opacity: 1; }

/* ---------- home: the two modes ---------- */

.modes { display: grid; gap: 8px; width: min(100%, 20rem); }
.modes .btn { width: 100%; }

/* ---------- practice tests: the kinds of test, as rows ---------- */

.tests [data-start] {
  display: grid;
  gap: 2px;
  width: 100%;
  padding: 16px 0;
  border: 0;
  background: none;
  text-align: left;
}
.tests .toc-title { font-weight: 500; }
.tests [data-start]:active .toc-title { color: var(--accent); }
.tests-note { color: var(--muted); }
.tests-last { color: var(--faint); font-size: 0.875rem; }
/* Tapped, while the test is made: it stays pressed. */
.tests [data-start]:disabled .toc-title { color: var(--accent); }
/* With a test under way, a row asks before replacing it. */
.tests-ask { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 8px; margin-top: -4px; padding-bottom: 16px; }
.tests-ask > span:first-child { color: var(--muted); font-size: 0.875rem; }
/* The buttons keep together, to the right, wrapped under the words or not. */
.tests-ask-do { display: flex; gap: 8px; margin-left: auto; }
.tests-ask .btn { padding-inline: 12px; }
/* Under the full test, once your age is known: changing it, quietly. */
.tests-age { display: inline-block; margin: -20px 0 6px; padding: 10px 0; border: 0; background: none; color: var(--faint); font-size: 0.875rem; }
.tests-age:active { color: var(--muted); text-decoration: underline; text-underline-offset: 2px; }

/* Keeping your progress: a link to carry it elsewhere, folded away at the foot of the page. */
.keep { margin-top: 32px; }
.keep summary { display: inline-flex; align-items: center; min-height: 36px; color: var(--faint); font-size: 0.875rem; cursor: pointer; touch-action: manipulation; }
.keep summary:active { color: var(--muted); }
.keep[open] summary { color: var(--muted); }
.keep p { margin: 12px 0 0; color: var(--muted); }
.keep-add { display: grid; gap: 4px; margin-top: 24px; }
.keep-add label { color: var(--muted); }
.keep-field { display: flex; gap: 8px; }
.keep-field input {
  flex: 1;
  min-width: 0;
  min-height: 40px;
  padding: 8px 12px;
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  background: var(--raised);
  color: var(--ink);
  font: inherit; /* 16px: smaller, and Safari zooms in on a tap */
}
.keep-note { color: var(--muted); font-size: 0.875rem; }
.keep-note:empty { display: none; }

/* ---------- breadcrumb ---------- */

.crumbs { flex: 1; min-width: 0; }
.crumbs ol { display: flex; align-items: center; min-width: 0; margin: 0; padding: 0; list-style: none; }
.crumbs li { display: flex; align-items: center; flex: none; min-width: 0; }
.crumbs li:last-child { flex: 0 1 auto; }
.crumbs li + li::before { content: "/"; padding: 0 2px; color: var(--edge); font-size: 1rem; }
.crumbs a {
  display: block;
  min-height: 36px;
  padding: 8px 6px;
  border-radius: var(--radius);
  overflow: hidden;
  color: var(--muted);
  font-size: 0.875rem;
  line-height: 20px;
  text-decoration: none;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.crumbs a:active { background: var(--hover); color: var(--ink); }
.crumbs .crumb-home { display: grid; place-items: center; width: 36px; margin-left: -9px; padding: 0; }
.crumbs .crumb-home .icon { width: 19px; height: 19px; }

/* ---------- handbook contents ---------- */

/* Installed as an app, the status bar is translucent: cover what scrolls under it. */
main::before {
  content: "";
  position: fixed;
  inset: 0 0 auto;
  z-index: 20;
  height: env(safe-area-inset-top);
  background: var(--bg);
}
body { overflow-x: clip; }

.page-title { font-size: 1.5rem; font-weight: 650; line-height: 1.2; letter-spacing: -0.015em; text-wrap: balance; }
.bar + .page-title { margin: 8px 0 24px; }
.progress + .page-title { margin-bottom: 24px; }

.resume {
  display: grid;
  gap: 2px;
  margin-bottom: 24px;
  color: inherit;
  font-weight: 500;
  text-decoration: none;
}
.resume:active span:last-child { color: var(--accent); }

.toc { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--edge); }
.toc li { border-bottom: 1px solid var(--edge); }
.toc a {
  display: grid;
  grid-template-columns: 1.75rem minmax(0, 1fr) auto;
  gap: 12px;
  align-items: baseline;
  padding: 16px 0;
  color: inherit;
  text-decoration: none;
}
.toc a:active .toc-title { color: var(--accent); }
.toc-num { color: var(--faint); font-size: 0.875rem; }
.toc-state { color: var(--faint); font-size: 0.875rem; }
.toc-state .icon { width: 16px; height: 16px; color: var(--right); vertical-align: -3px; }

.credit { margin: 32px 0 24px; color: var(--faint); font-size: 0.75rem; }
.credit a { color: inherit; }

/* ---------- handbook reader ---------- */

/* The bar stays at the top, full width, frosted; a line along its foot is how far through the section you are. */
.hb-bar {
  position: sticky;
  top: env(safe-area-inset-top);
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 4px;
  min-height: 56px;
  margin-inline: calc(50% - 50vw);
  padding-inline: max(20px, calc(50vw - 50%));
  background: color-mix(in oklch, var(--bg) 80%, transparent);
  -webkit-backdrop-filter: blur(16px) saturate(1.4);
  backdrop-filter: blur(16px) saturate(1.4);
  border-bottom: 1px solid color-mix(in oklch, var(--edge) 70%, transparent);
}
.hb-overall { flex: none; padding-left: 8px; color: var(--faint); font-size: 0.875rem; }
/* Looked up from a test or its results: the way back, in the percentage's place. */
.hb-return {
  flex: none;
  min-height: 36px;
  margin-right: -8px;
  padding: 8px;
  border-radius: var(--radius);
  color: var(--accent);
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 20px;
  text-decoration: none;
}
.hb-return:active { background: var(--hover); }

/* The bar shows the path to the part; scrolled past the title, it shows the part. */
.hb-lead { position: relative; flex: 1; align-self: stretch; min-width: 0; }
.hb-lead > .crumbs, .hb-heading {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  transition: opacity 160ms, transform 160ms;
}
.hb-heading {
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: 1px;
  padding: 0;
  border: 0;
  background: transparent;
  text-align: start;
  opacity: 0;
  transform: translateY(6px);
  visibility: hidden;
}
.hb-heading > span { max-width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.hb-heading-section { color: var(--faint); font-size: 0.75rem; line-height: 16px; }
.hb-heading-title { font-size: 1rem; font-weight: 600; line-height: 20px; }
/* Scrolling back up brings the path back. */
.hb-bar[data-scrolled]:not([data-up]) .hb-heading { opacity: 1; transform: none; visibility: visible; }
.hb-bar[data-scrolled]:not([data-up]) .hb-lead > .crumbs { opacity: 0; transform: translateY(-6px); visibility: hidden; }
/* The section along the bar's foot: a segment per part, filled once read; the current one fills as you scroll. */
.hb-segs {
  position: absolute;
  /* Lined up with the text column (34rem wide, 20px padding), not the full-width bar. */
  inset: auto calc((100vw - min(100vw, 34rem)) / 2 + 20px) -1px;
  display: flex;
  align-items: flex-end;
  gap: 2px;
  height: 4px;
}
.hb-segs i { flex: 1; height: 2px; overflow: hidden; border-radius: 1px; background: var(--edge); }
.hb-segs i.is-read { background: color-mix(in oklch, var(--accent) 40%, var(--edge)); }
/* The part on screen, read before or not: taller, and filling as you scroll. */
.hb-segs i.is-current { height: 4px; background: color-mix(in oklch, var(--accent) 20%, var(--edge)); }
.hb-segs b {
  display: block;
  height: 100%;
  background: var(--accent);
  transform-origin: left;
  animation: hb-fill linear both;
  animation-timeline: scroll(root);
}
@keyframes hb-fill { from { transform: scaleX(0); } to { transform: scaleX(1); } }
@supports not (animation-timeline: scroll()) {
  .hb-segs b { display: none; }
  .hb-segs i.is-current { background: var(--accent); }
}

.hb { padding-bottom: 32px; font-size: 1.0625rem; line-height: 1.65; }
.hb-title { margin: 24px 0 16px; font-size: 1.75rem; }
/* "Skim", beside a part's title wherever the title is shown. */
.hb-skim {
  margin-left: 0.35em;
  color: var(--accent);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  white-space: nowrap;
}
/* In the bar, a long title is cut short before the label is. */
.hb-heading-title { display: flex; align-items: baseline; }
.hb-heading-title > span:first-child { min-width: 0; overflow: hidden; text-overflow: ellipsis; }
.hb-heading-title .hb-skim { flex: none; }

.toc-title.is-skim { color: var(--muted); }
/* In a list the label is faint: it shouldn't draw the eye to the parts that matter least. */
.toc .hb-skim { color: var(--faint); }

/* "Hard", in the quiz bar during a hard-mode test. */
.mode-tag {
  margin-right: 8px;
  color: var(--accent);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.hb-title + .hb-h3, .hb-title + .hb-h2 { margin-top: 0; }

[data-block] { scroll-margin-top: calc(72px + env(safe-area-inset-top)); }

.hb p { margin: 0 0 0.85em; }
.hb strong { font-weight: 650; }

/* A number to remember: tabular figures on a faint chip, so "15 mph" reads as a value, not as prose. */
.qty {
  padding: 0.05em 0.3em;
  border-radius: 4px;
  background: color-mix(in oklch, var(--accent) 9%, transparent);
  font-family: var(--font-mono);
  font-size: 0.9em;
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  letter-spacing: -0.02em;
  white-space: nowrap;
  -webkit-box-decoration-break: clone;
  box-decoration-break: clone;
}
.hb a:not([class]) { color: var(--accent); text-underline-offset: 2px; }
.hb-h2, .hb-h3, .hb-h4 { clear: both; text-wrap: balance; }
.hb-h2 { margin: 32px 0 12px; font-size: 1.5rem; font-weight: 650; line-height: 1.25; letter-spacing: -0.015em; }
.hb-h3 { margin: 24px 0 8px; font-size: 1.25rem; font-weight: 650; line-height: 1.3; letter-spacing: -0.01em; }
.hb-h4 { margin: 24px 0 4px; font-size: 1em; font-weight: 650; line-height: 1.4; }

.hb-list { margin: 0 0 1em; padding-left: 1.25em; }
.hb-list li { margin: 0.35em 0; padding-left: 0.15em; }
.hb-list li::marker { color: var(--faint); }
.hb-list li > p { margin: 0 0 0.4em; }
.hb-list ul { margin: 0.35em 0 0; padding-left: 1.1em; }

.hb-note { margin: 16px 0; padding: 2px 0 2px 14px; border-left: 2px solid var(--accent); }
.hb-note .eyebrow { display: block; margin-bottom: 2px; color: var(--accent); }
.hb-note p { margin: 0; }

.hb-figure { position: relative; margin: 16px 0; }
/* Drawn smaller than it is: a tap opens it full size. */
.hb-figure.is-shrunk img { cursor: zoom-in; }
.hb-zoom {
  position: absolute;
  top: 6px;
  right: 6px;
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  padding: 0;
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  background: color-mix(in oklch, var(--raised) 85%, transparent);
  color: var(--muted);
}
.hb-zoom:active { background: var(--hover); color: var(--ink); }
.hb-zoom .icon { width: 16px; height: 16px; }
.zoom {
  width: 100vw;
  height: 100dvh;
  max-width: none;
  max-height: none;
  margin: 0;
  padding: 0;
  border: 0;
  overflow: auto;
  overscroll-behavior: contain;
  background: var(--bg);
}
.zoom::backdrop { background: var(--bg); }
.zoom-figure { display: grid; place-items: center; width: max-content; min-width: 100%; min-height: 100%; padding: 56px 16px 16px; }
.zoom img { display: block; border-radius: 4px; background: #fff; }
@media (prefers-color-scheme: dark) { .zoom img { filter: brightness(0.92); } }
.zoom-close { position: fixed; top: max(8px, env(safe-area-inset-top)); right: max(8px, env(safe-area-inset-right)); }
html:has(.zoom[open]) { overflow: hidden; }
/* The handbook's drawings assume a white page: on ours, multiplied, their white is the page's.
   In the dark they keep a white ground, a little dimmed. */
.hb-figure img { display: block; max-width: 100%; height: auto; border-radius: 4px; background: #fff; mix-blend-mode: multiply; }
@media (prefers-color-scheme: dark) { .hb-figure img { filter: brightness(0.92); mix-blend-mode: normal; } }
/* A sign sits beside the text that explains it, which keeps to its own column rather than wrapping under it. */
.hb-figure.is-small { float: left; margin: 4px 16px 8px 0; }
.hb-figure.is-small + :is(p, ul, ol) { display: flow-root; }
.hb-figure figcaption { margin-top: 4px; color: var(--faint); font-size: 0.875rem; line-height: 1.4; }
.hb-figures { clear: both; display: flex; flex-wrap: wrap; align-items: flex-end; gap: 16px; margin: 16px 0; }
.hb-figures .hb-figure { flex: 0 1 auto; min-width: 0; margin: 0; float: none; }

.hb-terms { margin: 0; }
.hb-terms dt { margin-top: 16px; font-weight: 650; }
.hb-terms dd { margin: 2px 0 0; color: var(--muted); }

/* Arriving from a link: the block is marked, then the mark fades. */
.hb-flash { animation: hb-flash 2s ease-out; border-radius: 4px; }
@keyframes hb-flash {
  from { background: color-mix(in oklch, var(--sticker) 45%, transparent); box-shadow: 0 0 0 6px color-mix(in oklch, var(--sticker) 45%, transparent); }
  to { background: transparent; box-shadow: 0 0 0 6px transparent; }
}

.section-title { margin: 4px 0 24px; }
/* Under the parts, faint and small: there for whoever looks, not asking to be followed. The padding makes it a tap target without moving the text. */
.section-questions { display: inline-block; margin-top: 24px; padding-block: 10px; color: var(--faint); font-size: 0.875rem; text-decoration: none; }
.section-questions:active { color: var(--muted); text-decoration: underline; text-underline-offset: 2px; }

/* A section's questions (views/questions.js): rows by part, the answer folded away. */
.qa-part { margin-top: 32px; }
.qa-part h2 { margin-bottom: 8px; font-size: 1.0625rem; font-weight: 600; }
.qa-part h2 a { color: inherit; text-decoration: none; }
.qa-part h2 a:active { color: var(--accent); }
.qa-choices { margin: 0; padding-left: 20px; color: var(--muted); }
.qa-answer summary {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  color: var(--accent);
  font-size: 0.875rem;
  cursor: pointer;
  touch-action: manipulation;
}
.qa-answer[open] { display: grid; gap: 4px; }
.qa-from { color: var(--faint); font-size: 0.75rem; }
.qa-from a { color: inherit; }

/* Below anything floated (a sign at the end of a part), always on its own. */
.hb-end { clear: both; padding-top: 40px; }
.hb-practice { margin-bottom: 24px; }
.hb-next {
  display: grid;
  gap: 2px;
  margin-top: 48px;
  padding: 16px 0;
  border-block: 1px solid var(--edge);
  color: inherit;
  font-weight: 600;
  text-decoration: none;
}
.hb-next:active span:last-child { color: var(--accent); }
.hb-end .hb-next { margin-top: 0; padding-block: 20px; font-size: 1.25rem; }
/* The part before, under the way on: small, since reading goes forward. */
.hb-prev { display: inline-block; margin-top: 8px; padding-block: 10px; color: var(--faint); font-size: 0.875rem; text-decoration: none; }
.hb-prev:active { color: var(--muted); }
/* Under the practice button, no rule as well: one edge is enough. */
.hb-practice + .hb-next { border-top: 0; padding-top: 8px; }
/* A section's link to the next: unruled and larger, so it reads as the way on rather than one more part. */
.section-next { margin-top: 32px; padding: 0; border: 0; font-size: 1.25rem; line-height: 1.3; }
.section-questions + .section-next { margin-top: 24px; }

/* Hover, for a pointer that hovers: after a tap, a hover style would stay on until the next tap elsewhere.
   Every control has the same look pressed (:active, beside its rules above). */
@media (hover: hover) {
  .btn:hover { background: var(--hover); }
  .btn.primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
  .btn.quiet:hover { background: var(--hover); color: var(--ink); }
  .fine-links a:hover { color: var(--muted); }
  .back:hover { background: var(--hover); color: var(--ink); }
  .choice:not(:disabled):hover { background: var(--hover); }
  .source a:hover { text-decoration: underline; }
  .tests [data-start]:hover .toc-title { color: var(--accent); }
  .tests-age:hover, .keep summary:hover { color: var(--muted); text-decoration: underline; text-underline-offset: 2px; }
  .toast-close:hover { opacity: 1; }
  .crumbs a:hover { background: var(--hover); color: var(--ink); }
  .resume:hover span:last-child { color: var(--accent); }
  .toc a:hover .toc-title { color: var(--accent); }
  .section-questions:hover { color: var(--muted); text-decoration: underline; text-underline-offset: 2px; }
  .qa-part h2 a:hover { color: var(--accent); }
  .hb-next:hover span:last-child { color: var(--accent); }
  .hb-return:hover { background: var(--hover); }
  .hb-zoom:hover { background: var(--hover); color: var(--ink); }
  .hb-prev:hover { color: var(--muted); text-decoration: underline; text-underline-offset: 2px; }
}

@media (prefers-reduced-motion: reduce) {
  .hb-flash { animation: none; }
}