/* ============================================================
   Cẩm nang — Matrix Hanzi handbook
   Inherits the app design system (vi/phat-am tokens):
   warm dark-first theme, light mode via html.light-mode,
   Plus Jakarta Sans / Inter / Noto Serif SC.
   Built for long-form evidence-dense reading:
   74ch measure, sticky TOC sidebar, theme-aware SVG charts.
   ============================================================ */

:root {
  --color-bg: #17130f;
  --color-card: #292119;
  --color-soft: #342a21;
  --color-text: #f6ede0;
  --color-muted: #b8aa98;
  --color-line: rgba(214, 176, 111, 0.2);
  --color-gold: #d09a43;
  --color-gold-dark: #8d5918;
  --color-green: #27836a;
  --color-red: #a94736;

  --shadow-md: 0 18px 45px rgba(0, 0, 0, 0.27);
  --shadow-lg: 0 35px 100px rgba(0, 0, 0, 0.46);

  --font-ui: 'Plus Jakarta Sans', 'Inter', sans-serif;
  --font-han: 'Noto Serif SC', 'Microsoft YaHei', serif;
  --font-body: 'Inter', 'Noto Serif SC', sans-serif;

  --bg: var(--color-bg);
  --card: var(--color-card);
  --soft: var(--color-soft);
  --text: var(--color-text);
  --muted: var(--color-muted);
  --line: var(--color-line);

  /* chart palette */
  --ch-grid: rgba(214, 176, 111, 0.14);
  --ch-bar: #d09a43;
  --ch-bar2: #27836a;
  --ch-bar3: #a94736;
  --ch-line: #d09a43;
  --ch-dot: #f6ede0;

  color-scheme: dark;
}

html.light-mode {
  --color-bg: #f6f3ea;
  --color-card: #fffdf8;
  --color-soft: #efeadd;
  --color-text: #202722;
  --color-muted: #6b6f68;
  --color-line: rgba(32, 39, 34, 0.14);
  --color-gold: #a26b21;
  --color-gold-dark: #7a4f16;
  --color-green: #1f6b57;
  --color-red: #93392a;

  --shadow-md: 0 14px 34px rgba(48, 36, 12, 0.12);
  --shadow-lg: 0 26px 70px rgba(48, 36, 12, 0.18);

  --ch-grid: rgba(32, 39, 34, 0.1);
  --ch-bar: #a26b21;
  --ch-bar2: #1f6b57;
  --ch-bar3: #93392a;
  --ch-line: #a26b21;
  --ch-dot: #202722;

  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16.5px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--color-gold); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; }

.skip {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--card); color: var(--text); padding: 10px 16px; border-radius: 0 0 10px 0;
}
.skip:focus { left: 0; }

.wrap { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ---------- progress ---------- */
.progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0;
  background: linear-gradient(90deg, var(--color-gold-dark), var(--color-gold));
  z-index: 60; transition: width 90ms linear;
}

/* ---------- header ---------- */
.top {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.top-inner {
  max-width: 1200px; margin: 0 auto; padding: 10px 24px;
  display: flex; align-items: center; gap: 18px;
}
.brand {
  font-family: var(--font-ui); font-weight: 800; font-size: 1.02rem;
  color: var(--text); white-space: nowrap;
}
.brand:hover { text-decoration: none; color: var(--color-gold); }
.brand-han {
  font-family: var(--font-han); color: var(--color-gold);
  font-size: 1.25rem; margin-right: 2px;
}
.nav { margin-left: auto; display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.nav a { color: var(--muted); font-size: 0.9rem; font-family: var(--font-ui); font-weight: 600; white-space: nowrap; }
.nav a:hover { color: var(--color-gold); text-decoration: none; }
.lang-switch { border: 1px solid var(--line); border-radius: 999px; padding: 3px 12px; }
.lang-switch.disabled { opacity: 0.45; cursor: not-allowed; }
.theme-btn, .menu-btn {
  background: var(--soft); border: 1px solid var(--line); color: var(--text);
  border-radius: 10px; width: 38px; height: 38px; cursor: pointer; font-size: 1.05rem;
}
.theme-btn:hover, .menu-btn:hover { border-color: var(--color-gold); }
.menu-btn { display: none; }

/* ---------- layout ---------- */
.layout-inner {
  display: grid; grid-template-columns: 270px minmax(0, 1fr);
  gap: 40px; align-items: start; padding-top: 34px; padding-bottom: 70px;
}
.sidebar {
  position: sticky; top: 78px;
  max-height: calc(100vh - 100px); overflow-y: auto;
  padding: 18px 16px; border: 1px solid var(--line); border-radius: 16px;
  background: var(--card); font-size: 0.86rem;
}
.side-label {
  font-family: var(--font-ui); font-weight: 700; font-size: 0.72rem;
  letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted);
  margin: 6px 0 8px;
}
.side-chapters, .side-sections { list-style: none; margin: 0 0 20px; padding: 0; }
.side-chapters li a, .side-sections li a {
  display: block; padding: 4px 10px; border-radius: 8px;
  color: var(--muted); border-left: 2px solid transparent;
}
.side-chapters li a:hover, .side-sections li a:hover { color: var(--text); background: var(--soft); text-decoration: none; }
.side-chapters li.current a {
  color: var(--color-gold); border-left-color: var(--color-gold);
  background: var(--soft); font-weight: 600;
}
.side-sections li a.active { color: var(--color-gold); border-left-color: var(--color-gold); }
.side-sections { font-size: 0.8rem; }

main.chapter { min-width: 0; }

/* ---------- hero ---------- */
.hero {
  display: grid; grid-template-columns: minmax(0, 1fr) 300px;
  gap: 30px; align-items: center; margin-bottom: 34px;
}
.hero.narrow { grid-template-columns: minmax(0, 1fr); }
.eyebrow {
  font-family: var(--font-ui); font-weight: 700; font-size: 0.8rem;
  letter-spacing: 0.14em; text-transform: uppercase; color: var(--color-gold);
  margin: 0 0 10px;
}
.hero h1 {
  font-family: var(--font-ui); font-weight: 800;
  font-size: clamp(1.7rem, 3.4vw, 2.5rem); line-height: 1.2; margin: 0 0 14px;
}
.lead { font-size: 1.06rem; color: var(--muted); margin: 0 0 14px; }
.hero-fig { margin: 0; text-align: center; }
.hero-fig img {
  border-radius: 18px; border: 1px solid var(--line);
  box-shadow: var(--shadow-md); width: 100%; aspect-ratio: 1; object-fit: cover;
}
.hero-fig.big img { aspect-ratio: 1; max-width: 340px; }
.hero-fig figcaption { font-size: 0.72rem; color: var(--muted); margin-top: 8px; }

.pill {
  display: inline-block; border-radius: 999px; padding: 5px 14px;
  font-size: 0.82rem; font-family: var(--font-ui); font-weight: 600;
}
.pill.warn {
  border: 1px solid var(--color-gold); color: var(--color-gold);
  background: color-mix(in srgb, var(--color-gold) 8%, transparent);
  white-space: normal; line-height: 1.5;
}

/* ---------- summary card ---------- */
.summary-card {
  background: var(--card); border: 1px solid var(--line);
  border-left: 4px solid var(--color-gold);
  border-radius: 14px; padding: 20px 26px; margin: 0 0 30px;
}
.summary-card h2 {
  font-family: var(--font-ui); font-size: 1rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--color-gold); margin: 0 0 10px;
}
.summary-card p { margin: 8px 0; }
.summary-card ul { margin: 8px 0; }

/* ---------- charts ---------- */
.charts-row { display: grid; gap: 22px; margin: 0 0 30px; }
.chart-card {
  margin: 0; background: var(--card); border: 1px solid var(--line);
  border-radius: 14px; padding: 20px 22px;
}
.chart-title {
  font-family: var(--font-ui); font-size: 1.02rem; font-weight: 700;
  margin: 0 0 12px; color: var(--text);
}
.chart { width: 100%; height: auto; display: block; }
.chart-card figcaption {
  font-size: 0.78rem; color: var(--muted); line-height: 1.55;
  margin-top: 12px; border-top: 1px dashed var(--line); padding-top: 10px;
}
.ch-grid { stroke: var(--ch-grid); stroke-width: 1; }
.ch-axis { fill: var(--muted); font-size: 11px; font-family: var(--font-ui); }
.ch-label { fill: var(--text); font-size: 12.5px; font-family: var(--font-ui); font-weight: 600; }
.ch-value { fill: var(--text); font-size: 14px; font-family: var(--font-ui); font-weight: 700; }
.ch-note { fill: var(--muted); font-size: 11px; font-family: var(--font-ui); }
.ch-bar { fill: var(--ch-bar); }
.ch-bar-2 { fill: var(--ch-bar2); }
.ch-bar-3 { fill: var(--ch-bar3); }
.ch-bar-target { fill: none; stroke: var(--ch-bar); stroke-width: 2.5; stroke-dasharray: 6 5; }
.ch-tone { fill: none; stroke: var(--ch-line); stroke-width: 3.5; stroke-linecap: round; stroke-linejoin: round; }
.ch-line { fill: none; stroke: var(--ch-line); stroke-width: 3; stroke-linecap: round; }
.ch-line-dashed { stroke: var(--ch-bar3); stroke-width: 2.5; stroke-dasharray: 7 6; fill: none; }
.ch-dot { fill: var(--ch-dot); stroke: var(--ch-line); stroke-width: 2.5; }
.ch-dot-hollow { fill: var(--card); stroke: var(--ch-bar3); stroke-width: 2.5; }
.ch-cell { fill: var(--ch-bar); opacity: 0.75; }
.ch-cell-off { fill: var(--ch-grid); }
.ch-band { fill: var(--ch-bar); opacity: 0.16; }
.ch-band-core { fill: var(--ch-bar); opacity: 0.5; }

/* ---------- station CTA ---------- */
.cta-card {
  display: flex; gap: 22px; align-items: center;
  background: linear-gradient(135deg, color-mix(in srgb, var(--color-gold) 10%, var(--card)), var(--card));
  border: 1px solid var(--color-gold-dark); border-radius: 16px;
  padding: 22px 26px; margin: 0 0 30px;
}
.cta-card h3 { font-family: var(--font-ui); margin: 0 0 8px; font-size: 1.1rem; }
.cta-card p { margin: 0 0 10px; color: var(--muted); font-size: 0.94rem; }
.cta-card img { border-radius: 14px; border: 1px solid var(--line); flex: 0 0 auto; }
.cta-buttons { display: flex; gap: 10px; flex-wrap: wrap; margin: 12px 0; }
.btn {
  display: inline-block; background: var(--color-gold); color: #17130f;
  font-family: var(--font-ui); font-weight: 700; font-size: 0.92rem;
  padding: 10px 20px; border-radius: 12px; border: 1px solid var(--color-gold);
  cursor: pointer;
}
.btn:hover { filter: brightness(1.08); text-decoration: none; }
.btn.ghost { background: transparent; color: var(--color-gold); }
.btn.big { padding: 13px 26px; font-size: 1rem; }

/* ---------- prose ---------- */
.prose { max-width: 74ch; }
.prose h2 {
  font-family: var(--font-ui); font-weight: 800; font-size: 1.42rem;
  margin: 2.4em 0 0.7em; padding-left: 14px; line-height: 1.35;
  border-left: 4px solid var(--color-gold);
  scroll-margin-top: 84px;
}
.prose h3 {
  font-family: var(--font-ui); font-weight: 700; font-size: 1.12rem;
  margin: 1.8em 0 0.5em; scroll-margin-top: 84px;
}
.prose h4 { font-family: var(--font-ui); font-weight: 700; font-size: 1rem; margin: 1.4em 0 0.4em; }
.prose p { margin: 0.9em 0; }
.prose ul, .prose ol { padding-left: 1.4em; margin: 0.9em 0; }
.prose li { margin: 0.35em 0; }
.prose li ul { margin: 0.3em 0; }
.prose strong { color: var(--color-gold); font-weight: 700; }
html.light-mode .prose strong { color: var(--color-gold-dark); }
.prose code {
  background: var(--soft); border: 1px solid var(--line);
  border-radius: 6px; padding: 1px 6px; font-size: 0.88em;
}
.prose blockquote {
  margin: 1.2em 0; padding: 12px 20px;
  border-left: 3px solid var(--color-green); background: var(--soft);
  border-radius: 0 12px 12px 0; color: var(--muted);
}
.prose blockquote p { margin: 0.4em 0; }
.prose hr.rule { border: none; border-top: 1px dashed var(--line); margin: 2.4em 0; }
.table-wrap { overflow-x: auto; margin: 1.2em 0; border: 1px solid var(--line); border-radius: 12px; }
.prose table { border-collapse: collapse; width: 100%; font-size: 0.9rem; }
.prose th {
  background: var(--soft); font-family: var(--font-ui); font-weight: 700;
  text-align: left; padding: 10px 14px; border-bottom: 1px solid var(--line);
  white-space: nowrap;
}
.prose td { padding: 9px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
.prose tr:last-child td { border-bottom: none; }
.prose tbody tr:nth-child(even) { background: color-mix(in srgb, var(--soft) 45%, transparent); }

/* ---------- sources panel ---------- */
.sources-panel {
  background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  padding: 20px 26px; margin: 40px 0 10px; max-width: 74ch;
}
.sources-panel h2 {
  font-family: var(--font-ui); font-size: 1.02rem; margin: 0 0 6px;
  color: var(--color-gold); border: none; padding: 0;
}
.sources-note { font-size: 0.8rem; color: var(--muted); margin: 0 0 12px; }
.source-list { margin: 0; padding-left: 1.2em; font-size: 0.88rem; }
.source-list li { margin: 8px 0; line-height: 1.5; }
.src-meta { color: var(--muted); font-size: 0.82rem; }
.dot {
  display: inline-block; width: 9px; height: 9px; border-radius: 50%;
  margin-right: 6px; vertical-align: baseline;
}
.dot.live { background: var(--color-green); }
.dot.dead { background: var(--color-red); }
.dot.na { background: var(--muted); }

/* ---------- prev/next ---------- */
.prevnext {
  display: grid; grid-template-columns: 1fr 1fr; gap: 14px;
  margin: 26px 0 10px; max-width: 74ch;
}
.pn {
  border: 1px solid var(--line); border-radius: 14px; padding: 14px 18px;
  background: var(--card); color: var(--text);
}
.pn:hover { border-color: var(--color-gold); text-decoration: none; }
.pn span { display: block; font-size: 0.76rem; color: var(--muted); font-family: var(--font-ui); text-transform: uppercase; letter-spacing: 0.08em; }
.pn strong { font-family: var(--font-ui); font-size: 0.95rem; line-height: 1.4; display: block; margin-top: 4px; }
.pn.next { text-align: right; }

/* ---------- home ---------- */
main.home { padding: 40px 0 60px; }
.home-hero { grid-template-columns: minmax(0, 1fr) 340px; margin-bottom: 40px; }
.legend {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 24px 28px; margin-bottom: 36px;
}
.legend h2 { font-family: var(--font-ui); font-size: 1.2rem; margin: 0 0 14px; }
.legend-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; }
.lg {
  background: var(--soft); border-radius: 12px; padding: 14px 16px;
  border-top: 3px solid var(--color-gold);
}
.lg strong { display: block; font-family: var(--font-ui); margin-bottom: 4px; }
.lg span { font-size: 0.86rem; color: var(--muted); }
.note { font-size: 0.84rem; color: var(--muted); }

.chapter-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 18px; margin-bottom: 40px;
}
.chapter-card {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 16px; display: flex; flex-direction: column; gap: 8px;
  color: var(--text); transition: transform 160ms ease, border-color 160ms ease;
}
.chapter-card:hover { transform: translateY(-3px); border-color: var(--color-gold); text-decoration: none; }
.chapter-card img {
  width: 100%; aspect-ratio: 16 / 9; object-fit: cover;
  border-radius: 10px; border: 1px solid var(--line);
}
.cc-num {
  font-family: var(--font-ui); font-size: 0.72rem; font-weight: 700;
  letter-spacing: 0.12em; text-transform: uppercase; color: var(--color-gold);
}
.chapter-card strong { font-family: var(--font-ui); font-size: 1.02rem; line-height: 1.35; }
.cc-lead {
  font-size: 0.82rem; color: var(--muted); line-height: 1.55;
  display: -webkit-box; -webkit-line-clamp: 4; -webkit-box-orient: vertical; overflow: hidden;
}
.cc-pill {
  align-self: flex-start; font-size: 0.7rem; font-family: var(--font-ui); font-weight: 700;
  border: 1px solid var(--color-gold); color: var(--color-gold);
  border-radius: 999px; padding: 2px 10px;
}
.cc-pill.vi-only { border-color: var(--color-green); color: var(--color-green); }
.home-station { display: flex; }

/* ---------- method page ---------- */
.stats-card {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 22px 26px; margin-bottom: 30px;
}
.stats-card h2 { font-family: var(--font-ui); font-size: 1.15rem; margin: 0 0 14px; }
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px; }
.stat {
  background: var(--soft); border-radius: 12px; padding: 12px 14px;
  border-left: 3px solid var(--color-green);
}
.stat strong { display: block; font-family: var(--font-ui); font-size: 1.3rem; color: var(--color-gold); }
.stat span { font-size: 0.78rem; color: var(--muted); }

/* ---------- station wrapper ---------- */
.station-page { padding: 34px 0 60px; }
.embed-frame {
  border: 1px solid var(--line); border-radius: 18px; overflow: hidden;
  box-shadow: var(--shadow-md); margin: 24px 0 14px; background: var(--card);
}
.embed-frame iframe { display: block; width: 100%; height: 82vh; border: 0; }

/* ---------- chooser ---------- */
body.chooser { display: flex; min-height: 100vh; align-items: center; }
.chooser-main { width: 100%; text-align: center; }
.chooser-main h1 { font-family: var(--font-ui); font-size: clamp(1.4rem, 3vw, 2rem); margin-bottom: 30px; }
.chooser-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; max-width: 760px; margin: 0 auto 26px; }
.chooser-card {
  background: var(--card); border: 1px solid var(--line); border-radius: 18px;
  padding: 28px 24px; color: var(--text); text-align: left;
}
.chooser-card:hover { border-color: var(--color-gold); text-decoration: none; }
.chooser-card strong { display: block; font-family: var(--font-ui); font-size: 1.25rem; margin-bottom: 8px; color: var(--color-gold); }
.chooser-card span { font-size: 0.9rem; color: var(--muted); }
.matrix-link { color: var(--muted); font-family: var(--font-ui); }

/* ---------- footer ---------- */
.foot {
  border-top: 1px solid var(--line); margin-top: 40px;
  padding: 30px 0 40px; font-size: 0.84rem; color: var(--muted);
}
.foot p { margin: 8px 0; max-width: 90ch; }
.foot-links a { color: var(--muted); }
.foot-links a:hover { color: var(--color-gold); }
.foot-matrix { font-family: var(--font-ui); font-size: 0.78rem; }

/* ---------- responsive ---------- */
@media (max-width: 1020px) {
  .layout-inner { grid-template-columns: minmax(0, 1fr); }
  .sidebar {
    position: fixed; top: 0; left: 0; bottom: 0; z-index: 70;
    width: 300px; max-width: 86vw; max-height: 100vh; border-radius: 0;
    transform: translateX(-105%); transition: transform 220ms ease;
    box-shadow: var(--shadow-lg);
  }
  .sidebar.open { transform: translateX(0); }
  .menu-btn { display: inline-block; order: 3; }
  .nav { gap: 10px; }
  .hero, .home-hero { grid-template-columns: minmax(0, 1fr); }
  .hero-fig { max-width: 320px; margin: 0 auto; }
  .cta-card { flex-direction: column; text-align: center; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .nav a:not(.lang-switch) { display: none; }
  .nav .menu-btn, .nav .theme-btn { display: inline-block; }
  .prevnext { grid-template-columns: 1fr; }
  .wrap { padding: 0 14px; }
  .top-inner { padding: 8px 14px; }
}
@media print {
  .top, .sidebar, .progress, .foot, .prevnext, .cta-card, .menu-btn { display: none !important; }
  body { background: #fff; color: #000; }
}