@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&family=Manrope:wght@400;500;600;700;800&display=swap');

:root {
  --paper: #f3efe5;
  --paper-deep: #e7e0d2;
  --ink: #18212b;
  --muted: #68717a;
  --line: #b9b1a2;
  --forward: #2867e8;
  --forward-soft: #dce7ff;
  --backward: #dc5b4d;
  --backward-soft: #f9ded9;
  --lime: #c8ec6c;
  --yellow: #f4c84c;
  --white: #fffdf7;
  --dark: #18212b;
  --mono: 'IBM Plex Mono', ui-monospace, monospace;
  --sans: 'Manrope', system-ui, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background:
    linear-gradient(rgba(24,33,43,.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(24,33,43,.045) 1px, transparent 1px),
    var(--paper);
  background-size: 24px 24px;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
}

button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  min-height: 64px;
  padding: 0 32px;
  border-bottom: 1px solid var(--ink);
  background: rgba(243,239,229,.94);
  backdrop-filter: blur(12px);
}
.wordmark { text-decoration: none; font-weight: 800; letter-spacing: -.02em; }
.wordmark span { display: inline-grid; place-items: center; width: 28px; height: 28px; margin-right: 8px; border: 1px solid var(--ink); font: 600 11px var(--mono); }
.topbar nav { display: flex; gap: 28px; }
.topbar nav a { color: var(--muted); font: 500 12px var(--mono); text-decoration: none; text-transform: uppercase; letter-spacing: .08em; }
.topbar nav a:hover { color: var(--ink); }
.lab-link { justify-self: end; padding: 8px 13px; border: 1px solid var(--ink); text-decoration: none; font: 600 12px var(--mono); box-shadow: 3px 3px 0 var(--ink); }
.lab-link:hover { transform: translate(1px, 1px); box-shadow: 2px 2px 0 var(--ink); }

.page-grid {
  display: grid;
  grid-template-columns: minmax(120px, 1fr) minmax(0, 1120px) minmax(120px, 1fr);
}
.chapter-mark {
  grid-column: 1;
  padding: 12px 20px 0;
  writing-mode: vertical-rl;
  justify-self: end;
  color: var(--muted);
  font: 600 11px var(--mono);
  letter-spacing: .1em;
}
.chapter-body, .hero-copy { grid-column: 2; }
.wide { min-width: 0; }
.chapter { padding: 104px 0; border-top: 1px solid var(--ink); }
.inverse { background: var(--dark); color: var(--paper); }
.inverse .chapter-mark, .inverse .section-heading p, .inverse .eyebrow { color: #9ba7b2; }

.hero { min-height: calc(100vh - 64px); padding: 12vh 0 8vh; align-items: center; }
.hero-copy { max-width: 750px; }
.eyebrow, .card-index {
  margin: 0 0 16px;
  color: var(--muted);
  font: 600 11px var(--mono);
  letter-spacing: .12em;
  text-transform: uppercase;
}
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 30px; font-size: clamp(58px, 8.2vw, 118px); line-height: .9; letter-spacing: -.065em; }
h2 { margin-bottom: 0; font-size: clamp(38px, 5vw, 70px); line-height: 1; letter-spacing: -.05em; }
h3 { line-height: 1.2; }
.lede { max-width: 710px; font-size: clamp(18px, 2vw, 24px); line-height: 1.5; color: #3e4851; }
.hero-rule { display: flex; align-items: center; gap: 18px; width: max-content; max-width: 100%; margin-top: 42px; padding: 14px 18px; border: 1px solid var(--ink); background: var(--white); font: 600 13px var(--mono); box-shadow: 6px 6px 0 var(--ink); }
.forward-ink { color: var(--forward); }
.backward-ink { color: var(--backward); }
.hero-card { grid-column: 2; width: min(500px, 44%); margin: -178px 0 0 auto; padding: 24px; border: 1px solid var(--ink); background: var(--white); transform: rotate(2deg); box-shadow: 10px 10px 0 var(--ink); }
.reader-line { display: grid; grid-template-columns: 72px 1fr auto; align-items: center; gap: 10px; padding: 12px 0; font: 600 11px var(--mono); }
.reader-line i { height: 3px; position: relative; }
.reader-line i:after { content: ''; position: absolute; top: -4px; width: 0; height: 0; border-top: 5px solid transparent; border-bottom: 5px solid transparent; }
.forward-line i { background: var(--forward); }
.forward-line i:after { right: 0; border-left: 8px solid var(--forward); }
.backward-line i { background: var(--backward); }
.backward-line i:after { left: 0; border-right: 8px solid var(--backward); }
.join-symbol { display: grid; grid-template-columns: 1fr 32px 1fr; text-align: center; align-items: center; margin: 14px 0; }
.join-symbol span { padding: 12px; border: 1px solid var(--ink); font: 600 11px var(--mono); }
.join-symbol b { font-size: 22px; }
.small-note { margin: 16px 0 0; color: var(--muted); font-size: 13px; }

.section-heading { display: flex; justify-content: space-between; align-items: end; gap: 60px; margin-bottom: 52px; }
.section-heading > div { flex: 1 1 70%; }
.section-heading > p { flex: 0 1 390px; margin: 0; color: var(--muted); }

.sequence-tools { display: flex; justify-content: space-between; gap: 20px; align-items: end; margin-bottom: 26px; }
.preset-group { display: flex; gap: 6px; }
.preset, .context-choice, .quiet-button, .run-button, .sample-button, .custom-sequence button {
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  padding: 9px 13px;
  cursor: pointer;
  font: 600 11px var(--mono);
  text-transform: uppercase;
  letter-spacing: .04em;
}
.preset.active, .context-choice.active { background: var(--ink); color: var(--paper); }
.custom-sequence { display: grid; grid-template-columns: auto minmax(180px, 330px) auto; gap: 8px; align-items: center; font: 500 11px var(--mono); color: var(--muted); }
.custom-sequence input { min-width: 0; padding: 10px; border: 1px solid var(--ink); border-radius: 0; background: var(--white); color: var(--ink); font: 500 12px var(--mono); }
.custom-sequence button { background: var(--yellow); }

.tape-lab { padding: 28px; border: 1px solid var(--ink); background: var(--white); box-shadow: 7px 7px 0 var(--ink); overflow-x: auto; }
.token-tape { display: grid; grid-auto-flow: column; grid-auto-columns: minmax(72px, 1fr); gap: 8px; min-width: 720px; padding: 16px 0; }
.token {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 74px;
  padding: 10px 5px;
  border: 1px solid var(--line);
  background: #f8f5ed;
  font: 600 13px var(--mono);
  transition: border-color .2s, background .2s, transform .2s;
}
.token:before, .token:after { position: absolute; display: grid; place-items: center; width: 20px; height: 20px; border-radius: 50%; color: white; font: 600 9px var(--mono); opacity: 0; transform: scale(.5); transition: .2s; }
.token:before { content: 'F'; top: -13px; left: 50%; margin-left: -10px; background: var(--forward); }
.token:after { content: 'B'; bottom: -13px; left: 50%; margin-left: -10px; background: var(--backward); }
.token.seen-forward { box-shadow: inset 0 4px 0 var(--forward); }
.token.seen-backward { box-shadow: inset 0 -4px 0 var(--backward); }
.token.current-forward:before, .token.current-backward:after { opacity: 1; transform: scale(1); }
.token.current-forward, .token.current-backward { border-color: var(--ink); background: white; transform: translateY(-2px); }
.direction-label { display: flex; align-items: center; gap: 10px; color: var(--muted); font: 500 10px var(--mono); text-transform: uppercase; }
.direction-label span { flex: 1; height: 2px; position: relative; }
.forward-label span { background: var(--forward); }
.forward-label span:after { content: ''; position: absolute; right: 0; top: -3px; border-top: 4px solid transparent; border-bottom: 4px solid transparent; border-left: 7px solid var(--forward); }
.backward-label { flex-direction: row-reverse; }
.backward-label span { background: var(--backward); }
.backward-label span:after { content: ''; position: absolute; left: 0; top: -3px; border-top: 4px solid transparent; border-bottom: 4px solid transparent; border-right: 7px solid var(--backward); }
.direction-label b { display: grid; place-items: center; width: 22px; height: 22px; color: white; border-radius: 50%; }
.forward-label b { background: var(--forward); }
.backward-label b { background: var(--backward); }

.transport { display: grid; grid-template-columns: auto auto auto 1fr auto; align-items: center; gap: 10px; margin: 24px 0; }
.run-button { background: var(--ink); color: white; }
.transport label, .transport output { font: 500 11px var(--mono); color: var(--muted); }
input[type='range'] { accent-color: var(--ink); }

.reader-decks { display: grid; grid-template-columns: 1fr .8fr 1fr; gap: 14px; }
.state-card, .token-card { min-width: 0; padding: 20px; border: 1px solid var(--ink); background: var(--white); }
.forward-card { border-top: 5px solid var(--forward); }
.backward-card { border-top: 5px solid var(--backward); }
.token-card { border-top: 5px solid var(--yellow); }
.state-head { display: flex; justify-content: space-between; gap: 10px; margin-bottom: 18px; font: 600 10px var(--mono); }
.state-head code { color: var(--muted); }
.state-card p { min-height: 50px; font-size: 13px; }
.state-card small { display: block; margin-top: 12px; color: var(--muted); font-size: 11px; }
.token-card strong { display: block; min-height: 52px; font: 600 20px var(--mono); }
.token-card p { color: var(--muted); font-size: 13px; }
.vector { display: grid; gap: 5px; }
.vector-bar { position: relative; height: 13px; background: var(--paper-deep); overflow: hidden; }
.vector-bar:after { content: ''; position: absolute; left: 50%; top: 0; bottom: 0; width: 1px; background: rgba(24,33,43,.35); }
.vector-bar i { position: absolute; top: 2px; bottom: 2px; min-width: 1px; transition: width .3s ease, left .3s ease; }
.forward-card .vector-bar i, #muVector .vector-bar i { background: var(--forward); }
.backward-card .vector-bar i, #sigmaVector .vector-bar i { background: var(--backward); }
.z-card .vector-bar i { background: var(--lime); }
.mini-embedding { display: grid; grid-template-columns: repeat(8, 1fr); gap: 3px; margin-top: 18px; }
.mini-embedding i { height: 28px; border: 1px solid var(--line); background: var(--paper); transition: background .2s; }
.mini-embedding i.on { background: var(--yellow); border-color: var(--ink); }

.merge-strip { display: grid; grid-template-columns: 1fr auto 1fr auto 1.2fr; align-items: stretch; margin-top: 14px; border: 1px solid var(--ink); background: var(--white); opacity: .42; transition: opacity .3s, transform .3s; }
.merge-strip.ready { opacity: 1; transform: translateY(-2px); box-shadow: 5px 5px 0 var(--ink); }
.merge-strip > div { padding: 16px; }
.merge-strip span, .merge-strip i { display: block; color: var(--muted); font: 500 9px var(--mono); }
.merge-strip b { display: block; margin-top: 4px; font: 700 18px var(--mono); }
.merge-strip > i, .merge-strip > strong { display: grid; place-items: center; padding: 10px; border-left: 1px solid var(--ink); border-right: 1px solid var(--ink); font-style: normal; }
.merged-block { background: var(--lime); }

.shape-pipeline { display: grid; grid-template-columns: repeat(9, auto); align-items: center; gap: 8px; overflow-x: auto; padding-bottom: 8px; }
.shape-stage { width: 176px; min-height: 126px; padding: 14px; border: 1px solid #63707d; background: transparent; color: var(--paper); text-align: left; cursor: pointer; }
.shape-stage span, .shape-stage b, .shape-stage code { display: block; }
.shape-stage span { color: #7f8c98; font: 500 10px var(--mono); }
.shape-stage b { margin: 17px 0 6px; font-size: 13px; }
.shape-stage code { color: #9ba7b2; font-size: 10px; }
.shape-stage.active { background: var(--lime); color: var(--ink); border-color: var(--lime); }
.shape-stage.active span, .shape-stage.active code { color: #435028; }
.shape-pipeline > i { width: 24px; height: 1px; background: #63707d; }
.shape-explainer { display: grid; grid-template-columns: .85fr 1.15fr; min-height: 360px; margin-top: 30px; border: 1px solid #63707d; }
.shape-copy { padding: 34px; border-right: 1px solid #63707d; }
.shape-copy h3 { font-size: clamp(28px, 3.4vw, 46px); letter-spacing: -.04em; }
.shape-copy > p:not(.card-index) { color: #b7c0c8; }
.shape-memory { padding: 14px; border-left: 4px solid var(--lime); background: #222d38; }
.shape-visual { display: grid; place-items: center; min-height: 360px; padding: 28px; overflow: hidden; }
.one-hot-grid { display: grid; grid-template-columns: repeat(13, 13px); gap: 4px; padding: 18px; border: 1px solid #63707d; }
.one-hot-grid i { width: 13px; height: 13px; background: #34414e; }
.one-hot-grid i.hot { background: var(--lime); box-shadow: 0 0 0 3px rgba(200,236,108,.18); }
.tensor-stack { position: relative; width: min(420px, 80%); height: 240px; }
.tensor-sheet { position: absolute; width: 80%; height: 75%; border: 1px solid #6b7884; background: #202b35; }
.tensor-sheet:nth-child(1) { left: 0; top: 20%; }
.tensor-sheet:nth-child(2) { left: 10%; top: 10%; }
.tensor-sheet:nth-child(3) { left: 20%; top: 0; background: linear-gradient(90deg, rgba(40,103,232,.35) 50%, rgba(220,91,77,.35) 50%); }
.tensor-sheet b { position: absolute; left: 18px; bottom: 14px; font: 600 13px var(--mono); }
.summary-bars { display: flex; align-items: stretch; width: min(500px, 90%); height: 170px; border: 1px solid #63707d; }
.summary-bars div { flex: 1; display: grid; place-items: center; font: 600 13px var(--mono); }
.summary-bars .blue { background: var(--forward); }
.summary-bars .red { background: var(--backward); }
.summary-bars .green { background: var(--lime); color: var(--ink); }
.head-split { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; width: min(500px, 90%); }
.head-split div { display: grid; place-items: center; min-height: 170px; border: 1px solid #63707d; font: 600 28px var(--mono); }
.head-split div:first-child { color: #8bb1ff; }
.head-split div:last-child { color: #ff9d92; }
.dimension-ledger { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 28px; border: 1px solid #63707d; }
.dimension-ledger > div { min-width: 0; padding: 20px; border-right: 1px solid #63707d; }
.dimension-ledger > div:last-child { border: 0; }
.dimension-ledger span { color: #8d99a5; font: 500 9px var(--mono); }
.dimension-ledger b { display: block; margin: 4px 0; color: var(--lime); font: 700 30px var(--mono); }
.dimension-ledger p { margin: 0; color: #9ba7b2; font-size: 12px; }

.gate-lab { border: 1px solid var(--ink); background: var(--white); box-shadow: 8px 8px 0 var(--ink); }
.gate-controls { display: grid; grid-template-columns: repeat(5, 1fr) auto; gap: 0; border-bottom: 1px solid var(--ink); }
.gate-controls label { display: grid; grid-template-columns: 1fr auto; gap: 8px; padding: 16px; border-right: 1px solid var(--ink); font: 500 10px var(--mono); }
.gate-controls input { grid-column: 1 / 3; width: 100%; }
.gate-controls output { font-weight: 600; }
.gate-controls button { margin: 12px; }
.forget-control { background: var(--forward-soft); }
.input-control { background: var(--backward-soft); }
.memory-machine { display: grid; grid-template-columns: 1fr auto 1fr auto 1.25fr; align-items: center; gap: 20px; padding: 42px; }
.memory-side { padding: 25px; border: 1px solid var(--ink); text-align: center; }
.memory-side span, .memory-tank-wrap > span { display: block; font: 600 10px var(--mono); }
.memory-side strong, .memory-tank-wrap strong { display: block; margin: 5px 0; font: 700 34px var(--mono); }
.memory-side small { color: var(--muted); font: 500 10px var(--mono); }
.old-side { background: var(--forward-soft); }
.new-side { background: var(--backward-soft); }
.math-operator { font-size: 26px; }
.memory-tank-wrap { text-align: center; }
.memory-tank { position: relative; height: 100px; margin-top: 9px; border: 2px solid var(--ink); overflow: hidden; background: var(--paper); }
.memory-tank em { position: absolute; left: 0; right: 0; top: 50%; height: 1px; background: var(--ink); }
.memory-tank i { position: absolute; left: 0; right: 0; background: var(--lime); transition: top .25s, height .25s; }
.live-equation { display: grid; grid-template-columns: 1fr 1.7fr; border-top: 1px solid var(--ink); }
.live-equation code, .live-equation span { padding: 14px 20px; font: 500 12px var(--mono); }
.live-equation code { border-right: 1px solid var(--ink); background: var(--dark); color: var(--paper); }
.output-equation code { background: var(--lime); color: var(--ink); }
.gate-analogy { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--ink); }
.gate-analogy > div { padding: 20px; border-right: 1px solid var(--ink); }
.gate-analogy > div:last-child { border: 0; }
.gate-analogy b, .gate-analogy span { display: block; }
.gate-analogy span { margin: 3px 0 12px; color: var(--muted); font: 500 10px var(--mono); }
.gate-analogy p { margin: 0; font-size: 12px; }
.scalar-warning { margin: 0; padding: 16px 20px; border-top: 1px solid var(--ink); background: var(--yellow); font: 600 11px var(--mono); }

.split-chapter { background: #dce7ff; }
.ambiguity-lab { padding: 28px; border: 1px solid var(--ink); background: var(--white); box-shadow: 8px 8px 0 var(--ink); }
.example-switch { display: flex; gap: 6px; }
.context-sentence { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; padding: 70px 20px; }
.context-word { padding: 9px 11px; border-bottom: 1px solid var(--line); font: 600 clamp(18px, 2.4vw, 30px) var(--mono); }
.context-word.focus { border: 2px solid var(--ink); background: var(--yellow); transform: rotate(-2deg); }
.context-word.past { color: var(--forward); }
.context-word.future { color: var(--backward); }
.evidence-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.evidence { padding: 22px; border: 1px solid var(--ink); }
.evidence span { font: 600 9px var(--mono); }
.evidence strong { display: block; margin: 8px 0; font: 600 18px var(--mono); }
.evidence p { margin: 0; color: var(--muted); font-size: 13px; }
.forward-evidence { border-top: 5px solid var(--forward); }
.backward-evidence { border-top: 5px solid var(--backward); }
.encoder-decoder-rule { display: grid; grid-template-columns: 1fr 80px 1fr; margin-top: 34px; align-items: center; }
.encoder-decoder-rule > div { padding: 28px; border: 1px solid var(--ink); background: var(--white); }
.encoder-decoder-rule > div:last-child { background: var(--ink); color: white; }
.encoder-decoder-rule span { font: 600 10px var(--mono); }
.encoder-decoder-rule b { display: block; margin: 8px 0; font-size: 22px; }
.encoder-decoder-rule p { margin: 0; color: var(--muted); }
.encoder-decoder-rule i { height: 1px; background: var(--ink); }

.latent-chapter { background: #ece6fa; }
.latent-flow { display: grid; justify-items: center; }
.latent-node, .z-card { min-width: 300px; padding: 22px; border: 1px solid var(--ink); background: var(--white); text-align: center; }
.latent-node span, .z-card > span, .latent-heads article > span { display: block; font: 600 9px var(--mono); }
.latent-node b, .z-card > b, .latent-heads article > b { display: block; font: 700 34px var(--mono); }
.latent-node code, .z-card > code, .latent-heads article > code { color: var(--muted); font: 500 11px var(--mono); }
.branch-lines { display: flex; width: 380px; height: 52px; }
.branch-lines i { flex: 1; border-bottom: 1px solid var(--ink); }
.branch-lines i:first-child { border-right: 1px solid var(--ink); transform: skewY(-12deg); transform-origin: right bottom; }
.branch-lines i:last-child { border-left: 1px solid var(--ink); transform: skewY(12deg); transform-origin: left bottom; }
.latent-heads { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; width: min(760px, 100%); }
.latent-heads article { padding: 20px; border: 1px solid var(--ink); background: var(--white); text-align: center; }
.vector.compact { margin-top: 14px; }
.vector.compact .vector-bar { height: 8px; }
.sample-equation { margin: 24px 0 10px; text-align: center; }
.sample-equation code { display: block; font: 600 24px var(--mono); }
.sample-equation span { color: var(--muted); font-size: 12px; }
.sample-button { margin-bottom: 18px; background: var(--yellow); box-shadow: 4px 4px 0 var(--ink); }
.z-card { width: min(500px, 100%); background: var(--dark); color: white; }
.latent-readout { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 30px; border: 1px solid var(--ink); background: var(--white); }
.latent-readout > div { min-width: 0; padding: 15px; border-right: 1px solid var(--ink); }
.latent-readout > div:last-child { border: 0; }
.latent-readout span { display: block; color: var(--muted); font: 500 9px var(--mono); }
.latent-readout code { display: block; margin-top: 5px; overflow-x: auto; white-space: nowrap; font-size: 10px; }
.architecture-receipt { margin-top: 34px; border: 1px solid var(--ink); background: var(--white); box-shadow: 7px 7px 0 var(--ink); }
.architecture-receipt > p { padding: 14px 18px; margin: 0; border-bottom: 1px solid var(--ink); background: var(--lime); color: var(--ink); }
.architecture-receipt > div { display: grid; grid-template-columns: 1fr 1.5fr; padding: 12px 18px; border-bottom: 1px solid var(--line); font: 500 12px var(--mono); }
.architecture-receipt > div:last-child { border: 0; }

.quiz-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.quiz-card { padding: 22px; border: 1px solid var(--ink); background: var(--white); }
.quiz-card > span { font: 600 10px var(--mono); color: var(--muted); }
.quiz-card h3 { min-height: 80px; margin: 14px 0 20px; }
.quiz-card button { display: block; width: 100%; margin: 7px 0; padding: 10px; border: 1px solid var(--line); background: transparent; text-align: left; cursor: pointer; font-size: 12px; }
.quiz-card button:hover { border-color: var(--ink); }
.quiz-card button.correct { background: var(--lime); border-color: var(--ink); }
.quiz-card button.wrong { background: var(--backward-soft); border-color: var(--backward); }
.quiz-feedback { min-height: 40px; margin: 14px 0 0; color: var(--muted); font-size: 12px; }
.memory-poster { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 54px; border: 1px solid var(--ink); background: var(--yellow); box-shadow: 10px 10px 0 var(--ink); }
.memory-poster > p { grid-column: 1 / 5; padding: 14px 18px; margin: 0; border-bottom: 1px solid var(--ink); }
.memory-poster > div { padding: 24px; border-right: 1px solid var(--ink); }
.memory-poster > div:last-child { border: 0; }
.memory-poster b { display: grid; place-items: center; width: 28px; height: 28px; margin-bottom: 28px; border: 1px solid var(--ink); border-radius: 50%; font: 600 11px var(--mono); }
.memory-poster span { display: block; font-weight: 800; }
.memory-poster p { margin: 8px 0 0; font-size: 13px; }

footer { display: flex; justify-content: space-between; gap: 30px; padding: 42px max(32px, calc((100% - 1120px) / 2)); border-top: 1px solid var(--ink); background: var(--white); }
footer b, footer span { display: block; }
footer span { margin-top: 4px; color: var(--muted); font-size: 12px; }
.footer-links { display: flex; gap: 22px; align-items: center; }
.footer-links a { font: 500 11px var(--mono); }

@media (max-width: 1100px) {
  .page-grid { grid-template-columns: 56px minmax(0, 1fr) 32px; }
  .chapter-body, .hero-copy, .hero-card { grid-column: 2; }
  .hero-card { position: relative; width: 430px; margin-top: -80px; }
  .reader-decks { grid-template-columns: 1fr 1fr; }
  .token-card { grid-column: 1 / 3; }
  .gate-controls { grid-template-columns: repeat(3, 1fr); }
  .gate-controls label:nth-child(3) { border-right: 0; }
  .gate-controls button { align-self: center; }
  .memory-machine { grid-template-columns: 1fr auto 1fr; }
  .memory-machine > .math-operator:nth-of-type(2) { display: none; }
  .memory-tank-wrap { grid-column: 1 / 4; }
}

@media (max-width: 760px) {
  .topbar { grid-template-columns: 1fr auto; padding: 0 14px; }
  .topbar nav { display: none; }
  .lab-link { padding: 6px 8px; }
  .page-grid { display: block; }
  .chapter-mark { writing-mode: horizontal-tb; padding: 0 0 22px; }
  .hero, .chapter { padding: 64px 16px; }
  .hero { min-height: auto; }
  h1 { font-size: 56px; }
  .hero-rule { width: 100%; gap: 8px; padding: 12px 10px; justify-content: space-between; font-size: 10px; }
  .hero-card { width: calc(100% - 12px); margin: 55px 0 0; transform: rotate(1deg); }
  .section-heading { display: block; margin-bottom: 32px; }
  .section-heading > p { margin-top: 20px; }
  .sequence-tools, .custom-sequence { display: block; }
  .preset-group { margin-bottom: 12px; overflow-x: auto; }
  .custom-sequence span { display: block; margin-bottom: 6px; }
  .custom-sequence input { width: calc(100% - 72px); }
  .tape-lab { padding: 20px 14px; }
  .transport { grid-template-columns: 1fr auto; }
  .transport label { grid-column: 1 / 2; }
  .transport input { grid-column: 1 / 2; width: 100%; }
  .reader-decks { display: block; }
  .reader-decks article { margin-bottom: 10px; }
  .merge-strip { grid-template-columns: 1fr auto 1fr; }
  .merge-strip > strong, .merged-block { grid-column: 1 / 4; border-top: 1px solid var(--ink); }
  .shape-explainer { grid-template-columns: 1fr; }
  .shape-copy { border: 0; border-bottom: 1px solid #63707d; }
  .dimension-ledger { grid-template-columns: 1fr 1fr; }
  .dimension-ledger > div:nth-child(2) { border-right: 0; }
  .dimension-ledger > div:nth-child(-n+2) { border-bottom: 1px solid #63707d; }
  .gate-controls { grid-template-columns: 1fr; }
  .gate-controls label { border-right: 0; border-bottom: 1px solid var(--ink); }
  .memory-machine { grid-template-columns: 1fr; padding: 24px; }
  .memory-machine .math-operator { display: block; }
  .memory-tank-wrap { grid-column: auto; }
  .live-equation { grid-template-columns: 1fr; }
  .live-equation code { border: 0; border-bottom: 1px solid var(--ink); }
  .gate-analogy { grid-template-columns: 1fr 1fr; }
  .gate-analogy > div:nth-child(2) { border-right: 0; }
  .gate-analogy > div:nth-child(-n+2) { border-bottom: 1px solid var(--ink); }
  .example-switch { overflow-x: auto; }
  .context-sentence { padding: 40px 4px; }
  .evidence-grid, .latent-heads, .latent-readout, .quiz-grid { grid-template-columns: 1fr; }
  .encoder-decoder-rule { grid-template-columns: 1fr; }
  .encoder-decoder-rule i { height: 30px; width: 1px; justify-self: center; }
  .branch-lines { width: 260px; }
  .latent-readout > div { border-right: 0; border-bottom: 1px solid var(--ink); }
  .architecture-receipt > div { grid-template-columns: 1fr; gap: 4px; }
  .quiz-card h3 { min-height: auto; }
  .memory-poster { grid-template-columns: 1fr 1fr; }
  .memory-poster > p { grid-column: 1 / 3; }
  .memory-poster > div:nth-child(3) { border-right: 0; }
  .memory-poster > div:nth-child(-n+3) { border-bottom: 1px solid var(--ink); }
  footer { display: block; padding: 32px 16px; }
  .footer-links { margin-top: 24px; flex-wrap: wrap; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *:before, *:after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
}