/* AI Foundations — shared styles
   Palette follows the AI Foundations Series decks: violet / plum / cyan. */

@import url('https://fonts.googleapis.com/css2?family=Atkinson+Hyperlegible:ital,wght@0,400;0,700;1,400&family=JetBrains+Mono:wght@400;600&family=Source+Serif+4:opsz,wght@8..60,500;8..60,600;8..60,700&display=swap');

:root {
  --paper: #FAFAFD;
  --surface: #FFFFFF;
  --ink: #1E1B3A;
  --ink-2: #4A4668;
  --ink-3: #6E6A8C;
  --line: #E4E1F2;
  --violet: #5B3FD1;
  --violet-strong: #4630B0;
  --violet-soft: #EEEAFD;
  --plum: #8A2F8F;
  --plum-soft: #F6E9F7;
  --cyan: #0B8C98;
  --cyan-soft: #E2F5F6;
  --amber: #9A5B00;
  --amber-soft: #FDF3E1;
  --good: #1F7A4A;
  --good-soft: #E4F4EA;
  --bad: #B3261E;
  --bad-soft: #FBE9E7;
  --code-bg: #F3F1FB;

  --serif: 'Source Serif 4', Cambria, Georgia, 'Times New Roman', serif;
  --sans: 'Atkinson Hyperlegible', Calibri, 'Segoe UI', system-ui, -apple-system, sans-serif;
  --mono: 'JetBrains Mono', Consolas, 'Courier New', monospace;

  --measure: 44rem;
  --radius-s: 6px;
  --radius-m: 12px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #15132A; --surface: #1D1A36; --ink: #ECEAF8; --ink-2: #C3BFDD; --ink-3: #9C97BD;
    --line: #34305A; --violet: #A493FF; --violet-strong: #C2B6FF; --violet-soft: #2A2455;
    --plum: #E08AE4; --plum-soft: #3A2244; --cyan: #4FD6E0; --cyan-soft: #16363D;
    --amber: #F2B45C; --amber-soft: #3A2C16; --good: #6FD69C; --good-soft: #173526;
    --bad: #FF8A80; --bad-soft: #3D1D1D; --code-bg: #25214A;
  }
}
:root[data-theme="dark"] {
  --paper: #15132A; --surface: #1D1A36; --ink: #ECEAF8; --ink-2: #C3BFDD; --ink-3: #9C97BD;
  --line: #34305A; --violet: #A493FF; --violet-strong: #C2B6FF; --violet-soft: #2A2455;
  --plum: #E08AE4; --plum-soft: #3A2244; --cyan: #4FD6E0; --cyan-soft: #16363D;
  --amber: #F2B45C; --amber-soft: #3A2C16; --good: #6FD69C; --good-soft: #173526;
  --bad: #FF8A80; --bad-soft: #3D1D1D; --code-bg: #25214A;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: var(--sans); font-size: 1.0625rem; line-height: 1.65;
}
img, svg { max-width: 100%; height: auto; }
a { color: var(--violet); text-underline-offset: 3px; }
a:hover { color: var(--violet-strong); }
:focus-visible { outline: 3px solid var(--cyan); outline-offset: 2px; border-radius: 4px; }
.skip { position: absolute; left: -999px; top: 0; background: var(--violet); color: #fff; padding: .5rem 1rem; z-index: 50; }
.skip:focus { left: 1rem; }

/* ---------- Top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; gap: 1rem;
  padding: .7rem clamp(1rem, 3vw, 2rem);
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: .6rem; text-decoration: none; color: var(--ink); font-family: var(--serif); font-weight: 600; font-size: 1.15rem; }
.brand svg { width: 28px; height: 28px; flex: none; }
.brand:hover { color: var(--ink); }
.topbar .spacer { flex: 1; }
.topbar a.plain { color: var(--ink-2); text-decoration: none; font-size: .95rem; }
.topbar a.plain:hover { color: var(--violet); }
.menu-btn {
  display: none; font: inherit; font-size: .95rem; color: var(--ink);
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-s);
  padding: .35rem .75rem; cursor: pointer;
}

/* ---------- Lesson layout ---------- */
.layout {
  display: grid; grid-template-columns: 16.5rem minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3.5rem);
  max-width: 78rem; margin: 0 auto; padding: 0 clamp(1rem, 3vw, 2rem);
}
.sidebar {
  position: sticky; top: 3.8rem; align-self: start;
  max-height: calc(100vh - 4.5rem); overflow-y: auto; padding: 1.75rem 0 2rem;
}
.sidebar h2 { font-family: var(--sans); font-size: .85rem; font-weight: 700; color: var(--ink-3); margin: 1.2rem 0 .35rem; }
.sidebar h2:first-child { margin-top: 0; }
.sidebar ol { list-style: none; margin: 0; padding: 0; }
.sidebar li { margin: 0; }
.sidebar li a {
  display: grid; grid-template-columns: 1.7rem 1fr; gap: .2rem;
  padding: .32rem .55rem; border-radius: var(--radius-s);
  color: var(--ink-2); text-decoration: none; font-size: .93rem; line-height: 1.35;
}
.sidebar li a .n { color: var(--ink-3); font-variant-numeric: tabular-nums; }
.sidebar li a:hover { background: var(--violet-soft); color: var(--ink); }
.sidebar li a[aria-current="page"] { background: var(--violet); color: #fff; }
.sidebar li a[aria-current="page"] .n { color: rgba(255,255,255,.75); }
.sidebar li a.done:not([aria-current]) .n { color: var(--good); }

main.lesson { padding: 2.25rem 0 4rem; min-width: 0; }
.lesson > * { max-width: var(--measure); }
.lesson > .wide { max-width: 58rem; }

.lesson-head { margin-bottom: 2rem; padding-bottom: 1.5rem; border-bottom: 1px solid var(--line); }
.lesson-meta { color: var(--ink-3); font-size: .95rem; margin: 0 0 .5rem; }
.lesson-meta strong { color: var(--plum); }
h1 {
  font-family: var(--serif); font-weight: 700;
  font-size: clamp(2rem, 4.6vw, 2.9rem); line-height: 1.12; letter-spacing: -.01em; margin: 0 0 .8rem;
}
.lede { font-size: 1.2rem; color: var(--ink-2); margin: 0; max-width: 40rem; }
h2 {
  font-family: var(--serif); font-weight: 600;
  font-size: clamp(1.5rem, 3vw, 1.85rem); line-height: 1.25; margin: 3rem 0 .8rem; scroll-margin-top: 5rem;
}
h3 { font-family: var(--sans); font-size: 1.15rem; font-weight: 700; margin: 2rem 0 .5rem; scroll-margin-top: 5rem; }
p { margin: 0 0 1rem; }
ul, ol { padding-left: 1.3rem; margin: 0 0 1rem; }
li { margin-bottom: .3rem; }
li::marker { color: var(--violet); }
code { font-family: var(--mono); font-size: .88em; background: var(--code-bg); padding: .1em .35em; border-radius: 4px; }
pre {
  font-family: var(--mono); font-size: .86rem; line-height: 1.55;
  background: var(--code-bg); border: 1px solid var(--line); border-radius: var(--radius-m);
  padding: 1rem 1.2rem; overflow-x: auto; margin: 0 0 1.25rem;
}
pre code { background: none; padding: 0; font-size: inherit; }
pre .c { color: var(--ink-3); font-style: italic; }
pre .k { color: var(--plum); font-weight: 600; }
pre .s { color: var(--cyan); }

.objectives { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-m); padding: 1.1rem 1.4rem .6rem; margin: 0 0 2rem; }
.objectives h2 { font-family: var(--sans); font-size: 1rem; font-weight: 700; margin: 0 0 .5rem; color: var(--violet); }

.callout { border-radius: var(--radius-m); padding: 1rem 1.25rem; margin: 1.5rem 0; border-left: 4px solid; }
.callout > :last-child { margin-bottom: 0; }
.callout .label { display: block; font-weight: 700; margin-bottom: .3rem; }
.analogy { background: var(--cyan-soft); border-color: var(--cyan); }
.analogy .label { color: var(--cyan); }
.activity { background: var(--plum-soft); border-color: var(--plum); }
.activity .label { color: var(--plum); }
.caution { background: var(--amber-soft); border-color: var(--amber); }
.caution .label { color: var(--amber); }
.remember { background: var(--violet-soft); border-color: var(--violet); }
.remember .label { color: var(--violet); }

.definition {
  font-family: var(--serif); font-size: 1.35rem; line-height: 1.45;
  margin: 1.5rem 0; padding: 0 0 0 1.2rem; border-left: 3px solid var(--plum);
}

.table-wrap { overflow-x: auto; margin: 1.25rem 0 1.75rem; border: 1px solid var(--line); border-radius: var(--radius-m); background: var(--surface); }
table { border-collapse: collapse; width: 100%; font-size: .95rem; line-height: 1.45; }
th, td { text-align: left; padding: .65rem .85rem; border-bottom: 1px solid var(--line); vertical-align: top; }
thead th { background: var(--violet-soft); font-weight: 700; white-space: nowrap; }
tbody tr:last-child > * { border-bottom: 0; }
tbody th { font-weight: 700; }
.table-wrap.dense table { font-size: .88rem; }
.table-wrap.dense th, .table-wrap.dense td { padding: .5rem .7rem; }
.stars { color: var(--amber); letter-spacing: .05em; white-space: nowrap; }
.tag { display: inline-block; font-size: .78rem; font-weight: 700; padding: .05rem .5rem; border-radius: 999px; background: var(--amber-soft); color: var(--amber); white-space: nowrap; }

.flow { display: flex; flex-wrap: wrap; align-items: center; gap: .45rem; margin: 1rem 0 1.4rem; }
.flow span { background: var(--surface); border: 1px solid var(--line); padding: .35rem .75rem; border-radius: 999px; font-size: .95rem; }
.flow span.hl { background: var(--violet); color: #fff; border-color: var(--violet); }
.flow i { font-style: normal; color: var(--ink-3); }

figure { margin: 1.75rem 0; }
figure.plate { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-m); padding: .75rem; }
figure.plate img { display: block; margin: 0 auto; border-radius: 6px; }
figure.art { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-m); padding: 1rem; }
figure.art svg { display: block; margin: 0 auto; }
figcaption { font-size: .9rem; color: var(--ink-3); margin-top: .6rem; text-align: center; }
figure.zoomable img { cursor: zoom-in; }

/* SVG diagram helpers */
.dg text { font-family: var(--sans); fill: var(--ink); }
.dg .muted { fill: var(--ink-3); }
.dg .box { fill: var(--surface); stroke: var(--line); stroke-width: 1.5; }
.dg .v { fill: var(--violet); } .dg .vs { fill: var(--violet-soft); }
.dg .p { fill: var(--plum); }   .dg .ps { fill: var(--plum-soft); }
.dg .c { fill: var(--cyan); }   .dg .cs { fill: var(--cyan-soft); }
.dg .a { fill: var(--amber); }  .dg .as { fill: var(--amber-soft); }
.dg .line { stroke: var(--ink-3); fill: none; }
.dg .line:not([stroke-width]) { stroke-width: 1.6; }
.dg .sv { stroke: var(--violet); } .dg .sp { stroke: var(--plum); } .dg .sc { stroke: var(--cyan); }
.dg .wt { fill: #fff; }
.dg .ink { fill: var(--ink); }

.duo { display: grid; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); gap: 1rem; margin: 1.25rem 0 1.75rem; }
.duo > div { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-m); padding: 1rem 1.2rem; }
.duo h3 { margin-top: 0; }
.duo > div > :last-child { margin-bottom: 0; }

.tasks { display: grid; grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr)); gap: .9rem; margin: 1rem 0 1.75rem; padding: 0; list-style: none; }
.tasks li { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-m); padding: .9rem 1.1rem; margin: 0; }
.tasks li h3 { margin: 0 0 .35rem; font-size: 1.05rem; }
.tasks li p { margin: 0 0 .4rem; font-size: .95rem; }
.tasks li .eg { color: var(--ink-2); }
.tasks li .apps { font-size: .87rem; color: var(--ink-3); margin: 0; }

/* Widgets */
.widget { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-m); padding: 1.1rem 1.25rem 1.25rem; margin: 1.75rem 0; }
.widget > .w-title { font-weight: 700; color: var(--violet); margin: 0 0 .25rem; }
.widget > .w-hint { color: var(--ink-3); font-size: .92rem; margin: 0 0 .9rem; }
.btn {
  font: inherit; font-size: .95rem; cursor: pointer; display: inline-block;
  background: var(--violet); color: #fff; border: 1px solid var(--violet);
  border-radius: var(--radius-s); padding: .45rem .95rem;
}
.btn:hover { background: var(--violet-strong); border-color: var(--violet-strong); color: #fff; }
.btn.ghost { background: transparent; color: var(--violet); }
.btn.ghost:hover { background: var(--violet-soft); color: var(--violet); }
.btn:disabled { opacity: .5; cursor: default; }
.controls { display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; margin: .75rem 0; }
.controls label { font-size: .93rem; color: var(--ink-2); }
input[type="text"], select {
  font: inherit; color: var(--ink); background: var(--paper);
  border: 1px solid var(--line); border-radius: var(--radius-s); padding: .45rem .7rem; min-width: 0;
}
input[type="text"] { flex: 1 1 16rem; }
input[type="range"] { accent-color: var(--violet); flex: 1 1 12rem; }
.readout { font-family: var(--mono); font-size: .92rem; background: var(--code-bg); border-radius: var(--radius-s); padding: .4rem .7rem; }

.bars { display: grid; gap: .35rem; margin-top: .6rem; }
.bar { display: grid; grid-template-columns: 6.5rem 1fr 3.8rem; align-items: center; gap: .6rem; font-size: .93rem; }
.bar .track { height: 14px; background: var(--violet-soft); border-radius: 999px; overflow: hidden; }
.bar .fill { height: 100%; background: var(--violet); border-radius: 999px; transition: width .35s ease; }
.bar.top .fill { background: var(--cyan); }
.bar .pct { font-family: var(--mono); font-size: .85rem; text-align: right; color: var(--ink-2); }
.gen-text { font-family: var(--serif); font-size: 1.25rem; padding: .6rem .8rem; background: var(--paper); border: 1px dashed var(--line); border-radius: var(--radius-s); min-height: 2.6rem; }
.gen-text .new { background: var(--cyan-soft); border-radius: 4px; padding: 0 .2rem; }

.tokens { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: .75rem; min-height: 2.5rem; }
.tok { display: inline-flex; flex-direction: column; align-items: center; border-radius: var(--radius-s); padding: .3rem .55rem; font-family: var(--mono); font-size: .9rem; border: 1px solid transparent; white-space: pre; }
.tok small { font-size: .72rem; opacity: .75; }
.tok:nth-child(4n+1) { background: var(--violet-soft); }
.tok:nth-child(4n+2) { background: var(--cyan-soft); }
.tok:nth-child(4n+3) { background: var(--plum-soft); }
.tok:nth-child(4n+4) { background: var(--amber-soft); }

.attn-words { display: flex; flex-wrap: wrap; gap: .35rem; margin: .5rem 0; }
.attn-words button {
  font: inherit; cursor: pointer; border: 1px solid var(--line); border-radius: var(--radius-s);
  padding: .3rem .6rem; color: var(--ink); background: var(--surface); transition: background .25s;
}
.attn-words button[aria-pressed="true"] { outline: 3px solid var(--plum); outline-offset: 1px; }
.attn-words button.strong { color: #fff; }

canvas.plot { width: 100%; height: auto; display: block; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-s); }

.rgb-row { display: flex; gap: 1rem; align-items: center; flex-wrap: wrap; }
.swatch { width: 5.5rem; height: 5.5rem; border-radius: var(--radius-s); border: 1px solid var(--line); flex: none; }
.rgb-sliders { flex: 1 1 14rem; display: grid; gap: .35rem; }
.rgb-sliders label { display: grid; grid-template-columns: 1.2rem 1fr 2.6rem; align-items: center; gap: .5rem; font-family: var(--mono); font-size: .9rem; }
.pixel-zone { display: flex; flex-wrap: wrap; gap: 1rem; align-items: flex-start; margin-top: 1rem; }
.pixel-grid { display: grid; grid-template-columns: repeat(10, 1fr); gap: 2px; width: 15rem; }
.pixel-grid div { aspect-ratio: 1; border-radius: 2px; cursor: pointer; }
.pixel-grid div:hover { outline: 2px solid var(--plum); }

.latent { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 1rem; align-items: start; }
@media (max-width: 34rem) { .latent { grid-template-columns: 1fr; } }
.latent-map { position: relative; aspect-ratio: 1; background:
    linear-gradient(var(--line) 1px, transparent 1px) 0 0 / 25% 25%,
    linear-gradient(90deg, var(--line) 1px, transparent 1px) 0 0 / 25% 25%, var(--paper);
  border: 1px solid var(--line); border-radius: var(--radius-s); cursor: crosshair; touch-action: none; }
.latent-map .dot { position: absolute; width: 16px; height: 16px; margin: -8px 0 0 -8px; border-radius: 50%; background: var(--plum); box-shadow: 0 0 0 4px color-mix(in srgb, var(--plum) 25%, transparent); pointer-events: none; }
.latent-map .ax { position: absolute; font-size: .75rem; color: var(--ink-3); pointer-events: none; }
.latent-out { text-align: center; }
.latent-out svg { width: 100%; max-width: 13rem; }

/* Quiz */
.quiz { margin: 3rem 0 1rem; }
.quiz .q { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-m); padding: 1rem 1.2rem; margin-bottom: .9rem; }
.quiz .q > p:first-child { font-weight: 700; margin-bottom: .6rem; }
.quiz .opts { display: grid; gap: .4rem; }
.quiz .opts button {
  font: inherit; text-align: left; cursor: pointer; color: var(--ink);
  background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-s); padding: .5rem .8rem;
}
.quiz .opts button:hover:not(:disabled) { border-color: var(--violet); }
.quiz .opts button.right { background: var(--good-soft); border-color: var(--good); }
.quiz .opts button.wrong { background: var(--bad-soft); border-color: var(--bad); }
.quiz .opts button:disabled { cursor: default; color: var(--ink); }
.quiz .explain { display: none; margin: .7rem 0 0; font-size: .95rem; color: var(--ink-2); }
.quiz .q.answered .explain { display: block; }
.quiz .score { color: var(--ink-3); font-size: .95rem; }

.takeaways { background: var(--violet); color: #fff; border-radius: var(--radius-m); padding: 1.3rem 1.5rem; margin: 2.5rem 0; }
.takeaways h2 { color: #fff; margin: 0 0 .6rem; font-size: 1.4rem; }
.takeaways ul { margin: 0; }
.takeaways li::marker { color: rgba(255,255,255,.7); }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .takeaways { background: var(--violet-soft); color: var(--ink); border: 1px solid var(--violet); }
  :root:not([data-theme="light"]) .takeaways h2 { color: var(--ink); }
}

dl.glossary { display: grid; grid-template-columns: minmax(8rem, 11rem) 1fr; border: 1px solid var(--line); border-radius: var(--radius-m); overflow: hidden; background: var(--surface); margin: 1rem 0 1.5rem; }
dl.glossary dt, dl.glossary dd { margin: 0; padding: .6rem .9rem; border-bottom: 1px solid var(--line); }
dl.glossary dt { font-weight: 700; background: var(--violet-soft); }
@media (max-width: 34rem) { dl.glossary { grid-template-columns: 1fr; } dl.glossary dt { border-bottom: 0; } }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 3.5rem; padding-top: 1.5rem; border-top: 1px solid var(--line); }
.pager a { display: block; padding: .9rem 1.1rem; border: 1px solid var(--line); border-radius: var(--radius-m); text-decoration: none; background: var(--surface); color: var(--ink); }
.pager a:hover { border-color: var(--violet); color: var(--ink); }
.pager small { display: block; color: var(--ink-3); font-size: .85rem; }
.pager span { font-weight: 700; color: var(--violet); }
.pager .next { text-align: right; grid-column: 2; }

footer.site { border-top: 1px solid var(--line); padding: 1.5rem clamp(1rem, 3vw, 2rem); color: var(--ink-3); font-size: .9rem; text-align: center; }
footer.site a { color: var(--ink-2); }

.lightbox { position: fixed; inset: 0; z-index: 60; background: rgba(12, 10, 28, .88); display: none; align-items: center; justify-content: center; padding: 1rem; cursor: zoom-out; }
.lightbox.open { display: flex; }
.lightbox img { max-height: 94vh; max-width: 96vw; border-radius: 8px; background: #fff; }

/* ---------- Home page ---------- */
.home-hero { max-width: 72rem; margin: 0 auto; padding: clamp(2.5rem, 6vw, 4.5rem) clamp(1rem, 3vw, 2rem) 1.5rem; }
.home-hero h1 { font-size: clamp(2.6rem, 7vw, 4.6rem); max-width: 14ch; margin-bottom: 1rem; }
.home-hero .lede { font-size: clamp(1.1rem, 2vw, 1.3rem); max-width: 38rem; }
.home-hero .by { margin-top: 1rem; color: var(--ink-3); font-size: .95rem; }
.home-hero .cta { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.5rem; }
.home-hero .cta a { text-decoration: none; }

.map-wrap { max-width: 72rem; margin: 0 auto; padding: 0 clamp(1rem, 3vw, 2rem); }
.map-scroll { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius-m); background: var(--surface); }
.map-scroll svg { display: block; min-width: 780px; width: 100%; height: auto; }
.map-note { color: var(--ink-3); font-size: .9rem; margin: .6rem 0 0; }
#map .edge { stroke: var(--line); stroke-width: 2; fill: none; }
#map .edge.main { stroke: color-mix(in srgb, var(--violet) 50%, var(--line)); stroke-width: 2.5; }
#map .track-label { font-family: var(--sans); font-size: 13px; font-weight: 700; fill: var(--plum); }
#map .track-rule { stroke: var(--plum); stroke-width: 1.5; opacity: .45; }
#map a { cursor: pointer; }
#map a circle.node { fill: var(--surface); stroke: var(--violet); stroke-width: 2.5; transition: fill .2s; }
#map a text.num { font-family: var(--sans); font-size: 15px; font-weight: 700; fill: var(--violet); text-anchor: middle; dominant-baseline: central; pointer-events: none; }
#map a text.lbl { font-family: var(--sans); font-size: 13px; fill: var(--ink-2); text-anchor: middle; }
#map a:hover circle.node, #map a:focus circle.node { fill: var(--violet); }
#map a:hover text.num, #map a:focus text.num { fill: #fff; }
#map a:focus { outline: none; }
#map a:focus-visible circle.node { stroke: var(--cyan); stroke-width: 4; }
#map a.done circle.node { stroke: var(--good); }
#map a.done text.num { fill: var(--good); }
#map a.done:hover circle.node { fill: var(--good); }
#map a.done:hover text.num { fill: #fff; }
#map .signal { fill: var(--cyan); }
@media (prefers-reduced-motion: reduce) { #map .signal { display: none; } }

.tracks { max-width: 72rem; margin: 0 auto; padding: 3rem clamp(1rem, 3vw, 2rem) 3rem; display: grid; grid-template-columns: repeat(auto-fit, minmax(21rem, 1fr)); gap: 2.5rem 3rem; }
.track h2 { font-size: 1.4rem; margin: 0 0 .25rem; }
.track > p { color: var(--ink-3); font-size: .95rem; margin: 0 0 .8rem; }
.track ol { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--line); }
.track li { margin: 0; border-bottom: 1px solid var(--line); }
.track li a { display: grid; grid-template-columns: 2.2rem 1fr auto; gap: .6rem; padding: .8rem .2rem; text-decoration: none; color: var(--ink); align-items: baseline; }
.track li a:hover .t { color: var(--violet); text-decoration: underline; }
.track .n { font-family: var(--serif); font-weight: 700; font-size: 1.25rem; color: var(--plum); }
.track .t { font-weight: 700; display: block; }
.track .d { color: var(--ink-2); font-size: .93rem; display: block; margin-top: .1rem; }
.track .m { color: var(--ink-3); font-size: .85rem; white-space: nowrap; }
.track li a.done .m { color: var(--good); }

.how { max-width: 72rem; margin: 0 auto; padding: 0 clamp(1rem, 3vw, 2rem) 3.5rem; }
.how h2 { margin-top: 0; }
.how .duo { margin: 0; }

@media (max-width: 60rem) {
  .layout { grid-template-columns: 1fr; }
  .menu-btn { display: inline-block; }
  .sidebar {
    position: fixed; inset: 3.4rem 0 0 0; z-index: 30; max-height: none;
    background: var(--paper); padding: 1.25rem 1.25rem 3rem; display: none; border-top: 1px solid var(--line);
  }
  body.nav-open .sidebar { display: block; }
  body.nav-open { overflow: hidden; }
}
@media (max-width: 34rem) {
  .pager { grid-template-columns: 1fr; }
  .pager .next { grid-column: 1; }
  .bar { grid-template-columns: 5rem 1fr 3.2rem; }
  .topbar a.plain.hide-s { display: none; }
}
@media print {
  .topbar, .sidebar, .pager, .widget, .menu-btn { display: none !important; }
  .layout { display: block; }
  .quiz .explain { display: block; }
}