:root {
  --header-h: 62px;
  --max: 1540px;
  --radius: 4px;
  --radius-soft: 9px;
  --blue: #55a2ff;
  --blue-strong: #2e79d8;
  --purple: #8b72ff;
  --purple-dark: #6751df;
  --pink: #ef6cae;
  --orange: #ff9a50;
  --yellow: #ffd65e;
  --teal: #34c6bb;
  --red: #ef626b;
  --green: #51cb7c;
}

body[data-theme="dark"] {
  --ink: #f4f7fb;
  --heading: #ffffff;
  --muted: #9aa8bb;
  --muted-2: #718096;
  --paper: #090e14;
  --paper-2: #0c121a;
  --card: #121923;
  --card-2: #161f2b;
  --card-3: #1b2532;
  --line: #263142;
  --line-strong: #344258;
  --input: #0d141d;
  --header: rgba(10, 15, 22, .96);
  --header-solid: #0a0f16;
  --hero-a: #2b507f;
  --hero-b: #34395f;
  --hero-c: #342744;
  --soft-purple: #24203b;
  --soft-blue: #17283c;
  --soft-green: #123229;
  --soft-yellow: #3b311a;
  --soft-red: #3e2025;
  --canvas: #0d141d;
  --canvas-grid: #233043;
  --shadow: 0 18px 50px rgba(0,0,0,.26);
}

body[data-theme="light"] {
  --ink: #172235;
  --heading: #0d1726;
  --muted: #5d6c80;
  --muted-2: #7b8798;
  --paper: #eef3f9;
  --paper-2: #f7f9fc;
  --card: #ffffff;
  --card-2: #f4f7fb;
  --card-3: #edf2f8;
  --line: #d8e0ea;
  --line-strong: #bac7d7;
  --input: #ffffff;
  --header: rgba(255,255,255,.94);
  --header-solid: #ffffff;
  --hero-a: #dcecff;
  --hero-b: #e8e5ff;
  --hero-c: #f5e8f2;
  --soft-purple: #eeeaff;
  --soft-blue: #e4f1ff;
  --soft-green: #e2f8f1;
  --soft-yellow: #fff5d5;
  --soft-red: #ffe8e9;
  --canvas: #f8fbff;
  --canvas-grid: #dce4ee;
  --shadow: 0 16px 42px rgba(36,58,87,.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, ui-sans-serif, "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.55;
  transition: background .2s ease, color .2s ease;
}
button, input, select, textarea { font: inherit; }
button { color: inherit; }
button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible, [tabindex]:focus-visible {
  outline: 3px solid rgba(85,162,255,.35);
  outline-offset: 2px;
}

.app-shell { min-height: 100vh; }
.site-header {
  height: var(--header-h);
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 0 clamp(15px, 2.2vw, 34px);
  background: var(--header);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}
.brand {
  display: flex;
  gap: 11px;
  align-items: center;
  flex: 0 0 auto;
  cursor: pointer;
  min-width: 214px;
}
.brand-mark {
  width: 34px;
  height: 34px;
  border: 1px solid #3e75bd;
  background: linear-gradient(145deg, #27395d, #3d295a);
  color: white;
  display: grid;
  place-items: center;
  font-weight: 900;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.06);
}
.brand-copy strong, .brand-copy span { display: block; }
.brand-copy strong { color: var(--heading); font-size: 15px; line-height: 1.15; }
.brand-copy span { color: var(--muted); font-size: 10px; margin-top: 3px; }
.main-nav { display: flex; align-items: stretch; gap: 2px; height: 100%; }
.nav-item {
  border: 0;
  border-bottom: 2px solid transparent;
  background: transparent;
  color: var(--muted);
  padding: 0 11px;
  cursor: pointer;
  font-size: 13px;
  transition: .16s ease;
}
.nav-item:hover { color: var(--heading); background: rgba(128,150,180,.07); }
.nav-item.active { color: var(--heading); border-bottom-color: var(--blue); }
.nav-item.kids-nav { color: #d79cff; }
.nav-item.kids-nav.active { border-bottom-color: #d79cff; }
.header-tools { margin-left: auto; display: flex; align-items: center; gap: 8px; min-width: 0; }
.search-wrap { position: relative; width: min(310px, 24vw); }
.search-wrap > span { position: absolute; left: 12px; top: 7px; color: var(--muted); font-size: 18px; }
.search-wrap input {
  width: 100%; height: 37px; border: 1px solid var(--line); background: var(--input); color: var(--ink);
  padding: 0 12px 0 36px; border-radius: var(--radius); box-shadow: none;
}
.search-wrap input::placeholder { color: var(--muted-2); }
.search-results {
  position: absolute; top: 44px; right: 0; width: min(500px, 88vw); max-height: 430px; overflow: auto;
  background: var(--card); border: 1px solid var(--line-strong); box-shadow: var(--shadow); padding: 6px;
}
.search-result { display: block; width: 100%; border: 0; background: transparent; text-align: left; padding: 11px; cursor: pointer; border-radius: var(--radius); }
.search-result:hover { background: var(--card-2); }
.search-result strong, .search-result small { display: block; }
.search-result small { color: var(--muted); }
.menu-button { display: none !important; }

.icon-button, .ghost-button, .primary-button, .secondary-button, .danger-button {
  border-radius: var(--radius); padding: 9px 14px; cursor: pointer; border: 1px solid transparent; font-weight: 750;
  transition: transform .15s ease, background .15s ease, border-color .15s ease;
}
.icon-button { background: var(--card); border-color: var(--line); width: 38px; height: 38px; padding: 0; }
.icon-button:hover, .ghost-button:hover { background: var(--card-2); border-color: var(--line-strong); }
.ghost-button { background: var(--card); border-color: var(--line); }
.primary-button { background: #4f91df; color: white; border-color: #5da3f7; box-shadow: 0 8px 20px rgba(44,116,203,.2); }
.primary-button:hover { background: #5ba1ef; transform: translateY(-1px); }
.secondary-button { background: var(--soft-purple); color: var(--heading); border-color: rgba(139,114,255,.35); }
.secondary-button:hover { border-color: var(--purple); }
.danger-button { background: var(--soft-red); color: var(--red); border-color: rgba(239,98,107,.35); }

.progress-strip {
  min-height: 43px;
  display: grid;
  grid-template-columns: auto minmax(160px, 360px) auto;
  align-items: center;
  gap: 16px;
  padding: 7px clamp(15px, 2.2vw, 34px);
  background: var(--paper-2);
  border-bottom: 1px solid var(--line);
}
.progress-copy { display: flex; gap: 9px; align-items: baseline; min-width: 0; }
.progress-copy strong { font-size: 11px; text-transform: uppercase; letter-spacing: .08em; }
.progress-copy span, .progress-strip small { color: var(--muted); font-size: 11px; }
.progress-track { --p: 0%; height: 20px; border: 1px solid var(--line); background: var(--card); position: relative; overflow: hidden; }
.progress-track::before { content: ""; position: absolute; inset: 0 auto 0 0; width: var(--p); background: linear-gradient(90deg, var(--blue-strong), var(--purple)); transition: width .25s ease; }
.progress-track span { position: relative; z-index: 1; height: 100%; display: grid; place-items: center; font-size: 10px; font-weight: 900; color: var(--heading); }

.main-stage { min-width: 0; }
.view { padding: 20px clamp(15px, 2vw, 32px) 64px; max-width: var(--max); margin: 0 auto; }
.hero {
  min-height: 400px;
  padding: clamp(32px, 5vw, 64px);
  display: grid;
  grid-template-columns: minmax(0, 1.18fr) minmax(320px, .82fr);
  gap: 30px;
  align-items: center;
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line-strong);
  background: linear-gradient(132deg, var(--hero-a) 0%, var(--hero-b) 56%, var(--hero-c) 100%);
  box-shadow: var(--shadow);
}
body[data-theme="dark"] .hero::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, transparent 55%, rgba(0,0,0,.35)); pointer-events: none; }
.hero-copy, .hero-visual { position: relative; z-index: 1; }
.eyebrow { font-size: 11px; text-transform: uppercase; letter-spacing: .105em; font-weight: 900; color: var(--blue); }
.hero h1 { color: var(--heading); font-size: clamp(44px, 5.4vw, 76px); line-height: .98; margin: 10px 0 18px; letter-spacing: -.045em; max-width: 850px; }
.hero h1 span { color: #bca9ff; }
.hero p { max-width: 720px; font-size: clamp(16px, 1.35vw, 20px); color: var(--ink); opacity: .9; }
.button-row { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 22px; align-items: center; }
.hero-visual { min-height: 280px; display: grid; place-items: center; }
.machine-diagram { width: min(440px,100%); padding: 22px; background: rgba(9,14,20,.55); border: 1px solid rgba(255,255,255,.13); box-shadow: 0 18px 50px rgba(0,0,0,.22); }
body[data-theme="light"] .machine-diagram { background: rgba(255,255,255,.68); border-color: rgba(255,255,255,.9); }
.machine-flow { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr; gap: 7px; align-items: center; }
.machine-node { min-height: 88px; display: grid; place-items: center; text-align: center; padding: 10px; background: var(--card); border: 1px solid var(--line); font-weight: 800; }
.machine-node:nth-child(1) { border-bottom: 4px solid var(--orange); }
.machine-node:nth-child(3) { border-bottom: 4px solid var(--purple); }
.machine-node:nth-child(5) { border-bottom: 4px solid var(--teal); }
.machine-arrow { color: var(--blue); font-weight: 900; }
.token-stream { margin-top: 14px; display: flex; gap: 5px; flex-wrap: wrap; }
.token-pill { padding: 5px 7px; background: var(--soft-purple); border: 1px solid rgba(139,114,255,.25); font: 11px ui-monospace, monospace; animation: pop .35s ease both; }
@keyframes pop { from { transform: scale(.8); opacity: 0; } }

.stats-row { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 12px; margin-top: 13px; }
.stat-card { background: var(--card); border: 1px solid var(--line); padding: 16px; }
.stat-card strong { display: block; color: var(--heading); font-size: 27px; }
.stat-card span { color: var(--muted); font-size: 12px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin: 39px 0 15px; }
.section-heading h2, .page-heading h1 { color: var(--heading); margin: 4px 0 0; font-size: clamp(27px, 3vw, 42px); line-height: 1.08; letter-spacing: -.03em; }
.section-heading p, .page-heading p { color: var(--muted); max-width: 820px; margin: 7px 0 0; }
.card-grid { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 12px; }
.topic-card, .demo-card, .lesson-card, .panel, .callout, .quiz-card, .journey-step, .lesson-section, .lab-panel, .glossary-card {
  background: var(--card); border: 1px solid var(--line); box-shadow: 0 8px 24px rgba(0,0,0,.08);
}
.topic-card, .demo-card, .lesson-card { min-height: 205px; padding: 17px; cursor: pointer; transition: transform .17s ease, border-color .17s ease, box-shadow .17s ease; }
.topic-card:hover, .demo-card:hover, .lesson-card:hover { transform: translateY(-3px); border-color: var(--line-strong); box-shadow: var(--shadow); }
.card-icon { width: 44px; height: 44px; display: grid; place-items: center; font-size: 21px; background: var(--soft-purple); border: 1px solid var(--line); }
.topic-card h3, .demo-card h3, .lesson-card h3 { color: var(--heading); margin: 13px 0 6px; }
.topic-card p, .demo-card p, .lesson-card p { margin: 0; color: var(--muted); font-size: 13px; }
.card-meta { margin-top: 14px; display: flex; justify-content: space-between; gap: 8px; color: var(--muted); font-size: 11px; }
.status-badge, .tag, .level-badge { display: inline-flex; align-items: center; padding: 3px 7px; font-size: 10px; font-weight: 850; text-transform: uppercase; letter-spacing: .04em; border: 1px solid var(--line); background: var(--card-2); }
.status-badge.done { background: var(--soft-green); color: var(--green); border-color: rgba(81,203,124,.28); }
.status-badge.kid { background: #332348; color: #d9a5ff; border-color: #644285; }
.tag { margin: 3px; color: var(--muted); }

.feature-banner { display: grid; grid-template-columns: 1.3fr .7fr; gap: 12px; margin-top: 12px; }
.feature-banner > div { padding: 22px; border: 1px solid var(--line); background: var(--card); }
.feature-banner .gradient-panel { background: linear-gradient(135deg, #244d7b, #3e2b60); color: white; }
.feature-banner h2 { margin: 5px 0; }
.feature-banner p { color: inherit; opacity: .82; }

.page-heading { display: flex; align-items: center; gap: 18px; margin-bottom: 22px; }
.page-heading > div:last-child { min-width: 0; }
.back-link { border: 0; padding: 0; background: transparent; color: var(--blue); font-weight: 800; cursor: pointer; align-self: flex-start; margin-top: 8px; white-space: nowrap; }
.demo-icon { width: 66px; height: 66px; display: grid; place-items: center; font-size: 32px; flex: 0 0 auto; background: var(--soft-purple); border: 1px solid var(--line); }
.filter-row { display: flex; flex-wrap: wrap; gap: 7px; margin: 16px 0 20px; }
.filter-chip { border: 1px solid var(--line); padding: 7px 11px; background: var(--card); cursor: pointer; color: var(--muted); }
.filter-chip.active { background: var(--blue-strong); color: white; border-color: var(--blue); }

.journey-map { display: grid; gap: 11px; }
.journey-step { display: grid; grid-template-columns: 58px 1fr auto; gap: 16px; align-items: center; padding: 17px; }
.step-number { width: 50px; height: 50px; display: grid; place-items: center; font-size: 18px; font-weight: 900; background: var(--card-2); border: 1px solid var(--line); }
.journey-step h3 { color: var(--heading); margin: 0 0 3px; }
.journey-step p { margin: 0; color: var(--muted); font-size: 13px; }

.lesson-layout, .demo-layout { display: grid; grid-template-columns: minmax(0,1fr) 300px; gap: 18px; align-items: start; }
.lesson-content, .demo-main { min-width: 0; }
.lesson-aside, .demo-guide { position: sticky; top: 119px; display: grid; gap: 11px; }
.lesson-hero { padding: 28px; background: linear-gradient(135deg,#244a78,#352653); border: 1px solid #465d7d; color: white; }
.lesson-hero .eyebrow { color: #acd2ff; }
.lesson-hero h1 { margin: 7px 0 10px; font-size: clamp(34px,4vw,54px); line-height: 1.03; }
.lesson-hero p { color: #d7e0ec; font-size: 17px; }
.reading-mode { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 18px; }
.reading-mode button { background: rgba(255,255,255,.08); color: white; border: 1px solid rgba(255,255,255,.16); padding: 7px 10px; cursor: pointer; }
.reading-mode button.active { background: white; color: #25344a; }
.lesson-section { padding: clamp(21px,3.2vw,34px); margin-top: 12px; }
.lesson-section h2 { color: var(--heading); font-size: 27px; margin: 0 0 12px; }
.lesson-section h3 { color: var(--heading); margin-top: 22px; }
.lesson-section p, .lesson-section li { color: var(--ink); opacity: .9; }
.code-block { background: #080c12; color: #dce8f7; padding: 16px; overflow: auto; font: 12px ui-monospace, SFMono-Regular, Consolas, monospace; white-space: pre-wrap; border: 1px solid #27364a; }
.simple-analogy { background: var(--soft-yellow); border-left: 4px solid var(--yellow); padding: 15px 17px; }
.deep-note { background: var(--soft-purple); border-left: 4px solid var(--purple); padding: 15px 17px; }
.technical-only { display: none; }
body.show-technical .technical-only { display: block; }
body.simple-mode .advanced-copy { display: none; }

.panel { padding: 18px; }
.panel h2, .panel h3 { color: var(--heading); margin-top: 0; }
.panel p { color: var(--muted); font-size: 13px; }
.guide-list { padding: 0; margin: 0; list-style: none; counter-reset: guide; display: grid; gap: 8px; }
.guide-list li { counter-increment: guide; padding-left: 30px; position: relative; font-size: 12px; color: var(--muted); }
.guide-list li::before { content: counter(guide); position: absolute; left: 0; width: 21px; height: 21px; display: grid; place-items: center; background: var(--soft-blue); color: var(--blue); font-weight: 900; border: 1px solid rgba(85,162,255,.22); }
.demo-main { display: grid; gap: 12px; }
.lab-panel { padding: clamp(19px,2.7vw,28px); }
.lab-panel h2, .lab-panel h3 { color: var(--heading); margin-top: 0; }
.lab-panel p, .lab-panel li { color: var(--muted); }
.control-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px; }
.control { display: grid; gap: 5px; }
.control label { font-size: 11px; font-weight: 900; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); }
.control input[type="text"], .control input[type="number"], .control textarea, .control select, .full-input, .control input:not([type]) {
  width: 100%; border: 1px solid var(--line); padding: 10px 11px; background: var(--input); color: var(--ink); border-radius: var(--radius);
}
.control textarea { min-height: 96px; resize: vertical; }
.control input[type="range"] { width: 100%; accent-color: var(--blue); }
.range-line { display: flex; justify-content: space-between; font-size: 11px; color: var(--muted); }
.output-box { border: 1px dashed var(--line-strong); background: var(--input); padding: 15px; min-height: 70px; }
.output-box.dark { background: #070b10; color: white; border-style: solid; }
.token-output { display: flex; flex-wrap: wrap; gap: 4px; align-content: flex-start; }
.token { padding: 5px 7px; font: 12px ui-monospace, monospace; cursor: help; color: #111827; }
.token:nth-child(5n+1) { background: #ffd9bc; }
.token:nth-child(5n+2) { background: #d8ccff; }
.token:nth-child(5n+3) { background: #bff0e8; }
.token:nth-child(5n+4) { background: #ffc9df; }
.token:nth-child(5n) { background: #c8ddff; }
.metric-strip { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 8px; margin-top: 12px; }
.metric { padding: 11px; background: var(--card-2); border: 1px solid var(--line); }
.metric strong, .metric span { display: block; }
.metric strong { color: var(--heading); font-size: 18px; }
.metric span { color: var(--muted); font-size: 10px; }
.bar-chart { display: grid; gap: 7px; }
.bar-row { display: grid; grid-template-columns: 90px 1fr 52px; gap: 8px; align-items: center; font-size: 12px; }
.bar-track { background: var(--card-3); height: 21px; overflow: hidden; }
.bar-fill { height: 100%; background: linear-gradient(90deg,var(--blue),var(--purple)); min-width: 1px; transition: width .22s ease; }
.context-track { display: flex; gap: 5px; overflow: hidden; padding: 9px; background: var(--card-2); min-height: 64px; align-items: center; border: 1px solid var(--line); }
.context-block { flex: 0 0 auto; max-width: 160px; padding: 8px; background: var(--card); font-size: 10px; border-bottom: 4px solid var(--teal); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.context-block.evicted { opacity: .35; border-bottom-color: var(--red); text-decoration: line-through; }
.memory-status { padding: 13px; font-weight: 800; }
.memory-status.remembered { background: var(--soft-green); color: var(--green); }
.memory-status.forgotten { background: var(--soft-red); color: var(--red); }
.canvas-wrap { overflow: hidden; border: 1px solid var(--line); background: var(--canvas); }
canvas { display: block; width: 100%; max-width: 100%; }
.loss-canvas { height: 210px; }
.matrix { display: grid; gap: 4px; overflow: auto; padding-bottom: 7px; }
.matrix-cell { min-width: 46px; min-height: 41px; display: grid; place-items: center; font-size: 10px; text-align: center; padding: 3px; }
.rag-chunks { display: grid; gap: 8px; }
.rag-chunk { border: 1px solid var(--line); padding: 11px; position: relative; }
.rag-chunk.selected { border-color: var(--blue); background: var(--soft-blue); }
.rag-score { position: absolute; right: 8px; top: 8px; font-size: 10px; font-weight: 900; color: var(--blue); }
.answer-box { padding: 16px; background: var(--soft-green); border-left: 4px solid var(--teal); }
.network-wrap { display: grid; grid-template-columns: 1fr 250px; gap: 14px; }
.network-display { min-height: 340px; background: #080d13; position: relative; overflow: hidden; border: 1px solid #253246; }
.network-svg { width: 100%; height: 340px; }
.training-log { max-height: 230px; overflow: auto; background: #080d13; color: #cbd7e8; padding: 11px; font: 11px ui-monospace, monospace; border: 1px solid #253246; }
.hardware-meter { height: 29px; background: var(--card-3); overflow: hidden; position: relative; border: 1px solid var(--line); }
.hardware-fill { height: 100%; background: linear-gradient(90deg,var(--teal),var(--blue),var(--purple)); transition: width .23s; }
.hardware-meter span { position: absolute; inset: 0; display: grid; place-items: center; font-size: 11px; font-weight: 900; }
.comparison-table { width: 100%; border-collapse: collapse; }
.comparison-table th, .comparison-table td { padding: 10px; border-bottom: 1px solid var(--line); text-align: left; font-size: 12px; }
.comparison-table th { color: var(--muted); }
.prompt-piece { border: 1px solid var(--line); padding: 12px; margin-top: 8px; background: var(--card-2); }
.prompt-piece strong { display: block; margin-bottom: 5px; }
.prompt-score { font-size: 43px; font-weight: 900; color: var(--blue); line-height: 1; }

.glossary-grid { columns: 3 280px; column-gap: 12px; }
.glossary-card { break-inside: avoid; margin: 0 0 12px; padding: 16px; }
.glossary-card h3 { color: var(--heading); margin: 0 0 4px; }
.glossary-card p { margin: 0; color: var(--muted); font-size: 13px; }
.glossary-card .technical-definition { margin-top: 9px; padding-top: 9px; border-top: 1px solid var(--line); font-size: 11px; }
.workbench-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px; }
.notes-area { min-height: 210px; }
.summary-card { background: linear-gradient(135deg,#244a78,#392656); color: white; border-color: #50607b; }
.summary-card p { color: #d7e0ec; }
.quiz-options { display: grid; gap: 7px; }
.quiz-option { text-align: left; padding: 10px; border: 1px solid var(--line); background: var(--card-2); color: var(--ink); cursor: pointer; }
.quiz-option.correct { background: var(--soft-green); border-color: rgba(81,203,124,.55); }
.quiz-option.wrong { background: var(--soft-red); border-color: rgba(239,98,107,.55); }
.callout { padding: 16px; }
.callout.warning { background: var(--soft-yellow); border-color: rgba(255,214,94,.35); }
.callout.success { background: var(--soft-green); border-color: rgba(81,203,124,.32); }

.kids-hero { padding: clamp(28px,5vw,60px); border: 1px solid #665181; background: linear-gradient(125deg,#314e82,#4c326e 58%,#70465e); color: white; position: relative; overflow: hidden; }
.kids-hero::after { content: "★  ✦  ●  ▲  ✧"; position: absolute; right: 3%; top: 14%; font-size: clamp(30px,6vw,78px); letter-spacing: .18em; color: rgba(255,255,255,.13); transform: rotate(-7deg); }
.kids-hero h1 { font-size: clamp(40px,6vw,72px); line-height: .98; margin: 8px 0 15px; max-width: 850px; }
.kids-hero p { max-width: 750px; color: #ecf2ff; font-size: 18px; }
.kid-missions { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 11px; margin-top: 12px; }
.kid-mission { padding: 18px; border: 1px solid var(--line); background: var(--card); cursor: pointer; }
.kid-mission strong { display: block; color: var(--heading); margin: 8px 0 4px; }
.kid-mission span { font-size: 12px; color: var(--muted); }
.big-emoji { font-size: 32px; }

.choice-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 10px; }
.choice-card { padding: 16px; border: 1px solid var(--line); background: var(--card-2); cursor: pointer; text-align: left; }
.choice-card:hover { border-color: var(--blue); }
.choice-card.correct { border-color: var(--green); background: var(--soft-green); }
.choice-card.wrong { border-color: var(--red); background: var(--soft-red); }
.pixel-grid { width: min(390px,100%); aspect-ratio: 1; display: grid; grid-template-columns: repeat(5,1fr); gap: 4px; padding: 5px; background: var(--card-3); border: 1px solid var(--line); }
.pixel-cell { border: 0; background: var(--input); cursor: pointer; }
.pixel-cell.on { background: var(--blue); }
.score-list { display: grid; gap: 7px; }
.score-row { display: grid; grid-template-columns: 120px 1fr 56px; gap: 8px; align-items: center; }
.demo-timeline { display: grid; gap: 8px; }
.timeline-step { display: grid; grid-template-columns: 34px 1fr; gap: 10px; align-items: start; padding: 11px; border: 1px solid var(--line); background: var(--card-2); }
.timeline-step .step-dot { width: 28px; height: 28px; display: grid; place-items: center; background: var(--soft-blue); color: var(--blue); font-weight: 900; }
.timeline-step.success .step-dot { background: var(--soft-green); color: var(--green); }
.timeline-step.fail .step-dot { background: var(--soft-red); color: var(--red); }
.check-row { display: flex; flex-wrap: wrap; gap: 10px; }
.check-pill { display: flex; align-items: center; gap: 6px; padding: 8px 10px; border: 1px solid var(--line); background: var(--card-2); }
.model-rank { display: grid; grid-template-columns: 46px 1fr auto; gap: 12px; align-items: center; padding: 13px; border: 1px solid var(--line); background: var(--card-2); margin-top: 8px; }
.model-rank:first-child { border-color: var(--blue); }
.model-rank .rank-num { font-size: 24px; font-weight: 900; color: var(--blue); }

.hidden { display: none !important; }
.toast { position: fixed; right: 22px; bottom: 22px; z-index: 100; background: #111a27; color: white; padding: 11px 15px; border: 1px solid #334359; box-shadow: var(--shadow); opacity: 0; transform: translateY(12px); pointer-events: none; transition: .2s; }
.toast.show { opacity: 1; transform: translateY(0); }

body.comfort-mode { font-size: 18px; }
body.comfort-mode .view { max-width: 1180px; }
body.comfort-mode p, body.comfort-mode li { line-height: 1.78; }
body.comfort-mode .card-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }

@media (max-width: 1240px) {
  .site-header { gap: 12px; }
  .brand { min-width: 185px; }
  .brand-copy span { display: none; }
  .nav-item { padding: 0 8px; }
  .search-wrap { width: 210px; }
  .surprise-button { display: none; }
  .card-grid { grid-template-columns: repeat(3,minmax(0,1fr)); }
}
@media (max-width: 980px) {
  .menu-button { display: grid !important; place-items: center; flex: 0 0 auto; }
  .site-header { padding: 0 13px; }
  .brand { min-width: 0; }
  .brand-copy span { display: none; }
  .main-nav { position: fixed; left: 0; right: 0; top: var(--header-h); height: auto; display: none; grid-template-columns: repeat(2,1fr); padding: 10px; background: var(--header-solid); border-bottom: 1px solid var(--line-strong); box-shadow: var(--shadow); }
  .main-nav.open { display: grid; }
  .nav-item { min-height: 44px; border: 1px solid var(--line); text-align: left; }
  .nav-item.active { border-color: var(--blue); }
  .header-tools { margin-left: auto; }
  .search-wrap { width: min(270px,33vw); }
  .progress-strip { grid-template-columns: 1fr minmax(140px,260px); }
  .progress-strip small { display: none; }
  .hero { grid-template-columns: 1fr; }
  .hero-visual { min-height: 220px; }
  .card-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .lesson-layout, .demo-layout { grid-template-columns: 1fr; }
  .lesson-aside, .demo-guide { position: static; grid-template-columns: repeat(2,minmax(0,1fr)); }
  .feature-banner { grid-template-columns: 1fr; }
  .kid-missions { grid-template-columns: repeat(2,minmax(0,1fr)); }
}
@media (max-width: 680px) {
  .brand-copy { display: none; }
  .site-header { gap: 7px; }
  .search-wrap { flex: 1; width: auto; }
  #toggleComfort { display: none; }
  .progress-strip { grid-template-columns: 1fr; gap: 5px; }
  .progress-copy { justify-content: space-between; }
  .view { padding: 14px 11px 52px; }
  .hero, .kids-hero { padding: 27px 20px; }
  .hero h1 { font-size: 43px; }
  .hero-visual { display: none; }
  .stats-row, .metric-strip { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .card-grid, body.comfort-mode .card-grid, .control-grid, .workbench-grid, .choice-grid { grid-template-columns: 1fr; }
  .lesson-aside, .demo-guide { grid-template-columns: 1fr; }
  .journey-step { grid-template-columns: 50px 1fr; }
  .journey-step button { grid-column: 1 / -1; }
  .page-heading { align-items: flex-start; flex-wrap: wrap; }
  .page-heading .back-link { width: 100%; }
  .network-wrap { grid-template-columns: 1fr; }
  .glossary-grid { columns: 1; }
  .kid-missions { grid-template-columns: 1fr; }
  .machine-flow { grid-template-columns: 1fr; }
  .machine-arrow { transform: rotate(90deg); }
  .comparison-table { display: block; overflow-x: auto; }
}