/* Sinosphere · 中华文化圈
   Ink-and-digital fusion · warm sepia-black + vermillion seal-red + imperial gold + jade
   Cormorant Infant (display) · Crimson Pro (body) · DM Mono (mono) · Noto Serif SC for Chinese */

:root {
  --bg: #0c0a08;
  --surface: #15110d;
  --surface-2: #1f1a13;
  --surface-3: #2c241b;
  --border: rgba(237, 228, 208, 0.10);
  --border-strong: rgba(237, 228, 208, 0.25);

  --ink: #ede4d0;
  --ink-dim: #b0a78f;
  --ink-mute: #786f5b;

  --seal:    #c43a2c;          /* vermillion seal red — primary */
  --gold:    #d4a743;          /* imperial gold */
  --jade:    #5a8a6a;          /* jade green — harmony */
  --ash:     #8a7e6b;          /* aged-ink wash */
  --crimson: #8a2f24;           /* deeper seal */

  --seal-soft:  rgba(196, 58, 44, 0.12);
  --gold-soft:  rgba(212, 167, 67, 0.12);
  --jade-soft:  rgba(90, 138, 106, 0.12);

  --shadow: 0 22px 56px rgba(0, 0, 0, 0.55);
  --radius: 4px;
  --radius-lg: 12px;
  --maxw: 1280px;

  --display: "Cormorant Infant", "Noto Serif SC", "Source Han Serif SC", serif;
  --body:    "Crimson Pro", "Noto Serif SC", "Source Han Serif SC", Georgia, serif;
  --mono:    "DM Mono", "JetBrains Mono", ui-monospace, monospace;
}

html[data-theme="light"] {
  --bg: #f5efe1;
  --surface: #fcf8eb;
  --surface-2: #ede5cf;
  --surface-3: #ddd2b6;
  --border: rgba(15, 12, 8, 0.14);
  --border-strong: rgba(15, 12, 8, 0.30);
  --ink: #1a140d;
  --ink-dim: #4a4030;
  --ink-mute: #756b53;
  --seal:    #98261b;
  --gold:    #8a6a1f;
  --jade:    #34664a;
  --ash:     #6e6453;
  --crimson: #6e1f17;
  --seal-soft:  rgba(152, 38, 27, 0.08);
  --gold-soft:  rgba(138, 106, 31, 0.08);
  --jade-soft:  rgba(52, 102, 74, 0.08);
  --shadow: 0 14px 32px rgba(15, 12, 8, 0.14);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--body);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

html[data-lang="en"] [lang="zh"] { display: none !important; }
html[data-lang="zh"] [lang="en"] { display: none !important; }

a { color: var(--gold); text-decoration: none; }
a:hover { text-decoration: underline; }

::selection { background: var(--seal-soft); color: var(--ink); }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 32px; }

/* ─── Topbar ─────────────────────────────── */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(140%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: 18px; height: 68px;
}
.brand {
  display: flex; align-items: center; gap: 12px;
  font-family: var(--display); font-size: 24px; letter-spacing: 0;
  color: var(--ink); font-style: italic;
}
.brand-mark {
  width: 32px; height: 32px; flex: 0 0 auto;
  background: var(--seal); color: var(--ink);
  border-radius: 4px;
  display: grid; place-items: center;
  font-family: var(--display); font-weight: 600; font-size: 22px;
  font-style: normal;
  box-shadow: 0 0 0 1px rgba(237, 228, 208, 0.15);
}
.brand small {
  font-family: var(--mono); font-size: 10.5px; color: var(--ink-mute);
  letter-spacing: 0.14em; text-transform: uppercase;
  margin-left: 4px; font-style: normal;
}
.nav { display: flex; gap: 22px; align-items: center; }
.nav a {
  color: var(--ink-dim); font-family: var(--mono); font-size: 12px;
  letter-spacing: 0.04em;
}
.nav a:hover { color: var(--ink); text-decoration: none; }

.controls { display: flex; gap: 8px; align-items: center; }
.lang-toggle, .theme-toggle {
  display: inline-flex; border: 1px solid var(--border-strong);
  border-radius: 999px; overflow: hidden; background: var(--surface);
}
.lang-toggle button, .theme-toggle button {
  font-family: var(--mono); font-size: 11.5px;
  background: transparent; color: var(--ink-dim); border: 0;
  padding: 6px 12px; cursor: pointer;
}
.lang-toggle button.active, .theme-toggle button.active {
  background: var(--ink); color: var(--bg);
}

@media (max-width: 1020px) { .nav { display: none; } }

/* ─── Hero ─────────────────────────────── */
.hero {
  padding: 130px 0 110px;
  border-bottom: 1px solid var(--border);
  position: relative; overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(45% 60% at 75% 25%, var(--seal-soft), transparent 60%),
    radial-gradient(40% 55% at 22% 80%, var(--gold-soft), transparent 60%),
    radial-gradient(30% 40% at 60% 95%, var(--jade-soft), transparent 60%);
  pointer-events: none;
}
.hero::after {
  content: ""; position: absolute; right: -80px; top: 50%; transform: translateY(-50%);
  width: 360px; height: 360px;
  background: radial-gradient(circle at center, var(--seal) 30%, transparent 60%);
  opacity: 0.03;
  pointer-events: none;
  border-radius: 50%;
}
.hero-inner { position: relative; }
.hero-eyebrow {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.18em;
  color: var(--seal); margin-bottom: 28px;
  text-transform: uppercase;
}
.hero h1 {
  font-family: var(--display); font-weight: 400;
  font-size: clamp(48px, 7.4vw, 100px);
  line-height: 1.04; letter-spacing: -0.012em;
  margin: 0 0 26px; color: var(--ink);
}
.hero h1 em {
  font-style: italic; color: var(--seal);
}
.hero h1 em.g { color: var(--gold); }
.hero h1 em.j { color: var(--jade); }

.hero-sub {
  font-size: 18.5px; color: var(--ink-dim); max-width: 780px;
  margin: 0 0 36px; line-height: 1.65;
}
.hero-meta {
  display: flex; flex-wrap: wrap; gap: 28px;
  font-family: var(--mono); font-size: 11.5px;
  color: var(--ink-mute); border-top: 1px solid var(--border);
  padding-top: 22px;
}
.hero-meta div { display: flex; flex-direction: column; gap: 4px; }
.hero-meta div span:first-child {
  font-family: var(--display); font-style: italic; font-size: 22px;
  color: var(--ink);
}

/* ─── Section ─────────────────────────────── */
section.module {
  padding: 100px 0; border-bottom: 1px solid var(--border);
  position: relative;
}
.section-head {
  display: grid; grid-template-columns: 220px 1fr; gap: 40px;
  margin-bottom: 44px; align-items: start;
}
.section-tag {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.10em;
  color: var(--ink-mute); text-transform: uppercase;
}
.section-tag .num { color: var(--seal); font-weight: 700; margin-right: 8px; }
.section-head h2 {
  font-family: var(--display); font-weight: 400; font-style: italic;
  font-size: clamp(34px, 4.8vw, 60px); margin: 0;
  line-height: 1.05; color: var(--ink); letter-spacing: -0.012em;
}
.section-lede {
  margin-top: 20px; color: var(--ink-dim); max-width: 820px;
  font-size: 17px; line-height: 1.7;
}
@media (max-width: 760px) { .section-head { grid-template-columns: 1fr; gap: 12px; } }

/* ─── Map / SVG card ─────────────────────────────── */
.map-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 28px;
  box-shadow: var(--shadow);
}
.map-svg-wrap { width: 100%; overflow: hidden; border-radius: 10px; }
.map-svg { width: 100%; height: auto; display: block; }
.map-legend {
  display: flex; flex-wrap: wrap; gap: 18px; margin-top: 18px;
  font-family: var(--mono); font-size: 11.5px; color: var(--ink-dim);
}
.map-legend .swatch {
  display: inline-block; width: 14px; height: 8px; border-radius: 2px;
  vertical-align: middle; margin-right: 6px;
}

/* ─── Cards ─────────────────────────────── */
.card-row {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 20px;
}
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 28px;
  position: relative;
  transition: border-color 0.18s, transform 0.18s;
}
.card:hover { border-color: var(--border-strong); transform: translateY(-2px); }
.card .kicker {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--accent, var(--seal)); margin-bottom: 12px;
}
.card.seal  { --accent: var(--seal); }
.card.gold  { --accent: var(--gold); }
.card.jade  { --accent: var(--jade); }
.card.ash   { --accent: var(--ash); }
.card h3 {
  font-family: var(--display); font-weight: 400; font-style: italic;
  font-size: 26px; margin: 0 0 12px; color: var(--ink); line-height: 1.2;
}
.card p { color: var(--ink-dim); font-size: 15px; line-height: 1.7; margin: 0 0 8px; }

/* ─── Philosopher cards ─────────────────────────────── */
.philos-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 18px;
}
.philos {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 24px; text-align: center;
}
.philos .glyph {
  font-family: var(--display); font-style: normal; font-weight: 600;
  font-size: 56px; color: var(--seal); line-height: 1; margin-bottom: 10px;
}
.philos .name {
  font-family: var(--display); font-style: italic; font-size: 22px;
  margin-bottom: 4px; color: var(--ink);
}
.philos .when {
  font-family: var(--mono); font-size: 10.5px; color: var(--ink-mute);
  letter-spacing: 0.06em; margin-bottom: 12px;
}
.philos .desc { font-size: 14px; color: var(--ink-dim); line-height: 1.65; text-align: left; }

/* ─── Comparison table ─────────────────────────────── */
.comp-table {
  width: 100%; border-collapse: collapse; font-size: 14.5px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg); overflow: hidden;
}
.comp-table th, .comp-table td {
  text-align: left; padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.comp-table th {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.10em;
  color: var(--seal);
  background: var(--surface-2);
  text-transform: uppercase;
}
.comp-table tr:last-child td { border-bottom: 0; }
.comp-table td:first-child { color: var(--ink); font-family: var(--display); font-style: italic; font-size: 17px; }

/* ─── Modernization grid ─────────────────────────────── */
.region-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
}
.region {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 24px;
  position: relative; overflow: hidden;
}
.region::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: var(--accent, var(--seal));
}
.region.cn { --accent: var(--seal); }
.region.jp { --accent: var(--crimson); }
.region.kr { --accent: var(--jade); }
.region.vn { --accent: var(--gold); }
.region.tw { --accent: var(--seal); }
.region.hk { --accent: var(--gold); }
.region.sg { --accent: var(--jade); }

.region .name {
  font-family: var(--display); font-style: italic; font-size: 22px;
  color: var(--ink); margin-bottom: 4px;
}
.region .since {
  font-family: var(--mono); font-size: 11px; color: var(--ink-mute);
  letter-spacing: 0.06em; margin-bottom: 12px;
}
.region p { color: var(--ink-dim); font-size: 14.5px; line-height: 1.65; margin: 0; }

/* ─── Calligraphy timeline (writing systems) ─────────────────── */
.script-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
}
.script {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 22px 18px; text-align: center;
}
.script .glyph {
  font-family: "Noto Serif SC", "Source Han Serif SC", serif;
  font-size: 64px; line-height: 1; color: var(--seal); margin-bottom: 12px;
}
.script .name {
  font-family: var(--display); font-style: italic; font-size: 18px;
  color: var(--ink); margin-bottom: 4px;
}
.script .when {
  font-family: var(--mono); font-size: 10px; color: var(--ink-mute);
  letter-spacing: 0.06em; margin-bottom: 10px;
}
.script .desc { font-size: 13px; color: var(--ink-dim); line-height: 1.55; text-align: left; }

/* ─── Simulator ─────────────────────────────── */
.sim-shell {
  display: grid; grid-template-columns: 320px 1fr; gap: 26px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 28px;
}
@media (max-width: 920px) { .sim-shell { grid-template-columns: 1fr; } }
.sim-shell h3 {
  font-family: var(--display); font-weight: 400; font-style: italic;
  font-size: 24px; margin: 0 0 16px;
}
.sim-controls label {
  display: block; font-family: var(--mono); font-size: 10.5px;
  letter-spacing: 0.10em; color: var(--ink-mute);
  margin-bottom: 6px; margin-top: 16px; text-transform: uppercase;
}
.sim-controls select, .sim-controls input[type="range"] {
  width: 100%;
  background: var(--surface-2); color: var(--ink);
  border: 1px solid var(--border-strong); border-radius: 6px;
  padding: 9px 12px; font-family: var(--mono); font-size: 13px;
}
.sim-output { display: flex; flex-direction: column; gap: 14px; }
.sim-output .sbar {
  display: grid; grid-template-columns: 200px 1fr 60px;
  gap: 12px; align-items: center;
  font-family: var(--mono); font-size: 12px; color: var(--ink-dim);
}
.sim-output .sbar .meter {
  height: 9px; border-radius: 4px;
  background: var(--surface-2); position: relative; overflow: hidden;
}
.sim-output .sbar .meter > i {
  position: absolute; left: 0; top: 0; bottom: 0;
  background: linear-gradient(90deg, var(--seal), var(--gold));
  transition: width 0.4s;
}
.sim-output .sbar .v { color: var(--ink); text-align: right; font-family: var(--display); font-size: 18px; font-style: italic; }
.sim-readout {
  font-family: var(--mono); font-size: 12.5px; color: var(--ink-dim);
  border: 1px dashed var(--border-strong);
  border-radius: 8px; padding: 14px 16px; margin-top: 8px;
  line-height: 1.7;
}

/* ─── AI ─────────────────────────────── */
.ai-shell {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 30px;
  box-shadow: var(--shadow);
}
.ai-prompts { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.ai-prompt {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.02em;
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: 999px; padding: 9px 16px; color: var(--ink-dim);
  cursor: pointer; transition: all 0.16s;
}
.ai-prompt:hover { color: var(--ink); border-color: var(--seal); }
.ai-input-row { display: flex; gap: 10px; }
.ai-input-row input {
  flex: 1; background: var(--surface-2); color: var(--ink);
  border: 1px solid var(--border-strong); border-radius: 8px;
  padding: 12px 16px; font-family: var(--body); font-size: 15px;
}
.ai-input-row button {
  background: var(--seal); color: var(--ink); border: 0;
  padding: 12px 24px; font-family: var(--mono); font-size: 12px;
  letter-spacing: 0.08em; text-transform: uppercase;
  border-radius: 8px; cursor: pointer; font-weight: 700;
}
.ai-input-row button:hover { background: var(--gold); color: var(--bg); }
.ai-output {
  margin-top: 22px; min-height: 80px;
  font-size: 16px; line-height: 1.78; color: var(--ink-dim);
  border-top: 1px solid var(--border); padding-top: 20px;
}
.ai-output strong { color: var(--ink); }
.ai-output em {
  font-style: normal; color: var(--seal); font-family: var(--mono);
  font-size: 12.5px; letter-spacing: 0.04em;
}
.ai-output p { margin: 0 0 12px; }

/* ─── Guardrails ─────────────────────────────── */
.guardrails {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 28px;
  border-left: 3px solid var(--seal);
}
.guardrails h3 { font-family: var(--display); font-style: italic; font-weight: 400; margin: 0 0 14px; font-size: 24px; }
.guardrails ul { margin: 0; padding-left: 22px; }
.guardrails li { color: var(--ink-dim); margin-bottom: 12px; font-size: 15px; line-height: 1.7; }

/* ─── Footer ─────────────────────────────── */
footer {
  padding: 70px 0 50px;
  font-family: var(--mono); font-size: 12px; color: var(--ink-mute);
  letter-spacing: 0.02em;
}
footer a { color: var(--ink-dim); }
footer .foot-row {
  display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap;
}
footer .links { display: flex; gap: 22px; flex-wrap: wrap; }

/* ─── Util ─────────────────────────────── */
.mono { font-family: var(--mono); }
.dim  { color: var(--ink-dim); }
.tag-seal  { color: var(--seal); }
.tag-gold  { color: var(--gold); }
.tag-jade  { color: var(--jade); }
.tag-ash   { color: var(--ash); }