:root {
  --bg: #f7f2e7;
  --bg-soft: #fbf8f1;
  --ink: #1d2328;
  --muted: #5d666f;
  --line: rgba(29, 35, 40, 0.12);
  --panel: rgba(255, 252, 246, 0.9);
  --accent: #b34f2e;
  --accent-soft: #f1c8b3;
  --sage: #cfe2db;
  --rose: #ead3dd;
  --gold: #f0d7a0;
  --shadow: 0 18px 50px rgba(71, 50, 27, 0.09);
  --radius-lg: 28px;
  --radius-md: 20px;
  --radius-sm: 14px;
  --mono: "SFMono-Regular", "Cascadia Code", "Fira Code", Consolas, monospace;
  --sans: "Avenir Next", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(179, 79, 46, 0.12), transparent 28%),
    radial-gradient(circle at top right, rgba(94, 132, 117, 0.12), transparent 26%),
    linear-gradient(180deg, #f9f4ea 0%, #f4ede1 100%);
  font-family: var(--sans);
  line-height: 1.65;
}

a {
  color: inherit;
  text-decoration: none;
}

code {
  padding: 0.1rem 0.36rem;
  border-radius: 0.5rem;
  background: rgba(24, 31, 35, 0.07);
  font-family: var(--mono);
  font-size: 0.92em;
}

.page-shell {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 28px;
  width: min(1500px, calc(100% - 48px));
  margin: 24px auto 56px;
}

.sidebar {
  position: sticky;
  top: 18px;
  align-self: start;
  display: grid;
  gap: 18px;
}

.brand-block,
.source-links,
.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

.brand-block,
.source-links {
  padding: 22px;
}

.brand-kicker,
.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.brand-block h1 {
  margin: 0 0 12px;
  font-size: 1.65rem;
  line-height: 1.2;
}

.brand-block p,
.source-links a {
  color: var(--muted);
}

.toc {
  display: grid;
  gap: 8px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(255, 249, 239, 0.72);
}

.toc a {
  padding: 10px 12px;
  border-radius: 12px;
  color: var(--muted);
  font-weight: 700;
  transition: 160ms ease;
}

.toc a:hover,
.toc a.active {
  color: var(--ink);
  background: rgba(179, 79, 46, 0.12);
}

.source-title {
  margin-bottom: 12px;
  font-weight: 800;
}

.source-links {
  display: grid;
  gap: 10px;
}

.content {
  display: grid;
  gap: 24px;
}

.panel {
  padding: 30px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  gap: 26px;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
}

.hero-copy h2 {
  margin: 0 0 14px;
  font-size: clamp(2rem, 3vw, 3.4rem);
  line-height: 1.08;
  max-width: 18ch;
}

.hero-lead {
  max-width: 64ch;
  font-size: 1.05rem;
  color: var(--muted);
}

.hero-actions {
  display: flex;
  gap: 12px;
  margin-top: 24px;
  flex-wrap: wrap;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 18px;
  border-radius: 999px;
  font-weight: 800;
}

.button.primary {
  color: #fff8f2;
  background: linear-gradient(135deg, #ab4524, #cf6f49);
}

.button.secondary {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.5);
}

.hero-visual {
  display: grid;
  gap: 16px;
}

.visual-card {
  padding: 20px;
  border-radius: var(--radius-md);
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.62), rgba(241, 216, 186, 0.8));
  border: 1px solid rgba(179, 79, 46, 0.12);
}

.visual-card.accent {
  background: linear-gradient(145deg, rgba(239, 247, 244, 0.85), rgba(209, 228, 220, 0.9));
}

.visual-label {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}

.chip-flow {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chip-flow span {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(29, 35, 40, 0.08);
  font-weight: 700;
}

.visual-card ul {
  margin: 0;
  padding-left: 18px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(1.65rem, 2vw, 2.5rem);
  line-height: 1.18;
}

.matrix-grid,
.stack-grid,
.roots-layout,
.compare-grid,
.loop-layout,
.chapter-grid,
.checklist-grid,
.file-map {
  display: grid;
  gap: 16px;
}

.matrix-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 20px;
}

.matrix-card,
.stack-card,
.root-card,
.compare-card,
.loop-card,
.chapter-card,
.check-card,
.file-item {
  padding: 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.6);
}

.matrix-card h3,
.stack-card h3,
.root-card h3,
.compare-card h3,
.loop-card h3 {
  margin-top: 0;
  margin-bottom: 8px;
}

.matrix-card p,
.stack-card p,
.root-card p,
.compare-card p,
.loop-card p,
.chapter-card em,
.file-item span {
  color: var(--muted);
}

.answer {
  margin-top: 12px;
  padding: 10px 12px;
  border-radius: 12px;
  background: rgba(179, 79, 46, 0.08);
  font-weight: 700;
}

.stack-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: 20px;
}

.stack-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  margin-bottom: 10px;
  border-radius: 50%;
  background: rgba(179, 79, 46, 0.14);
  color: var(--accent);
  font-weight: 800;
}

.note-strip {
  margin-top: 18px;
  padding: 16px 18px;
  border-radius: 16px;
  background: rgba(29, 35, 40, 0.06);
}

.roots-layout {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 20px;
}

.diagram-card {
  margin-top: 18px;
  padding: 18px;
  border-radius: var(--radius-md);
  background: linear-gradient(180deg, rgba(255, 252, 247, 0.95), rgba(244, 233, 214, 0.78));
  border: 1px solid var(--line);
}

.diagram-card svg {
  width: 100%;
  height: auto;
}

.svg-title {
  font-family: var(--sans);
  font-size: 22px;
  font-weight: 800;
  fill: #1d2328;
}

.svg-line,
.svg-note {
  font-family: var(--sans);
  font-size: 16px;
  fill: #59646b;
}

.svg-note {
  font-size: 14px;
  font-weight: 700;
}

.svg-arrow {
  stroke: #7f543a;
  stroke-width: 3.5;
  fill: none;
  stroke-linecap: round;
  marker-end: url(#none);
}

.box-a { fill: #f0d7a0; }
.box-b { fill: #e7d5bf; }
.box-c { fill: #d5e6df; }
.box-d { fill: #f7ead6; }
.box-e { fill: #ead3dd; }
.strip-box { fill: rgba(255, 255, 255, 0.68); }

.timeline {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: 12px;
  margin-top: 22px;
}

.stage-pill {
  padding: 14px 12px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.66);
}

.stage-pill strong {
  display: block;
  margin-bottom: 6px;
  font-size: 1rem;
}

.stage-pill span {
  color: var(--muted);
  font-size: 0.95rem;
}

.intent-boxes {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.intent-card {
  padding: 16px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.55);
}

.intent-card span {
  display: block;
  margin-bottom: 8px;
  font-weight: 800;
}

.intent-card code {
  display: inline-block;
  background: transparent;
  padding: 0;
}

.chain-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 18px;
  align-items: center;
}

.plain-list {
  margin: 0;
  padding-left: 20px;
}

.compare-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 20px;
}

.compare-card.danger {
  background: rgba(236, 209, 214, 0.48);
}

.compare-card.safe {
  background: rgba(207, 226, 219, 0.5);
}

.validation-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 20px;
}

.file-map {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 18px;
}

.file-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.loop-layout {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 20px;
}

.checklist-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 20px;
}

.check-card {
  min-height: 108px;
  display: flex;
  align-items: center;
  font-size: 1.03rem;
  font-weight: 700;
}

.chapter-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 20px;
}

.chapter-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-height: 156px;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.chapter-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 32px rgba(52, 41, 30, 0.12);
}

.chapter-card span {
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.chapter-card strong {
  font-size: 1.15rem;
}

.chapter-card em {
  font-style: normal;
}

@media (max-width: 1180px) {
  .page-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
  }

  .hero,
  .chain-grid,
  .matrix-grid,
  .stack-grid,
  .roots-layout,
  .timeline,
  .intent-boxes,
  .compare-grid,
  .validation-grid,
  .loop-layout,
  .checklist-grid,
  .chapter-grid,
  .file-map {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  .page-shell {
    width: min(100% - 24px, 100%);
    margin: 12px auto 30px;
    gap: 16px;
  }

  .panel,
  .brand-block,
  .source-links {
    padding: 20px;
  }

  .hero,
  .matrix-grid,
  .stack-grid,
  .roots-layout,
  .timeline,
  .intent-boxes,
  .compare-grid,
  .validation-grid,
  .loop-layout,
  .checklist-grid,
  .chapter-grid,
  .file-map,
  .chain-grid {
    grid-template-columns: 1fr;
  }

  .hero-copy h2 {
    max-width: none;
  }
}