/* China Regional Civilization Systems · 中国区域文明系统
   Dark ink default · cinematic geopolitical-statistical aesthetic
   Playfair Display (display) · Sora (body) · Fira Code (mono) */

:root {
  --bg: #0e1219;
  --surface: #161b25;
  --surface-2: #1f2531;
  --border: rgba(230, 226, 211, 0.12);
  --border-strong: rgba(230, 226, 211, 0.28);
  --ink: #e6e2d3;
  --ink-dim: #a9aebd;
  --ink-mute: #6f7585;

  --beijing: #c93a3a;
  --yangtze: #3a9b9b;
  --pearl:   #d65484;
  --hk:      #d4a017;
  --neutral: #7a8595;

  --shadow: 0 18px 48px rgba(0, 0, 0, 0.55);
  --radius: 4px;
  --radius-lg: 12px;
  --maxw: 1260px;
  --display: "Playfair Display", "Bodoni Moda", Georgia, serif;
  --body: "Sora", "Inter Tight", system-ui, sans-serif;
  --mono: "Fira Code", "JetBrains Mono", ui-monospace, monospace;
}

html[data-theme="light"] {
  --bg: #f4f0e3;
  --surface: #fdfaef;
  --surface-2: #ece6d3;
  --border: rgba(14, 18, 25, 0.16);
  --border-strong: rgba(14, 18, 25, 0.34);
  --ink: #14171e;
  --ink-dim: #4d5260;
  --ink-mute: #7a8090;
  --beijing: #a02828;
  --yangtze: #1f6f6f;
  --pearl:   #b03065;
  --hk:      #a37312;
  --neutral: #4a5260;
  --shadow: 0 14px 36px rgba(14, 18, 25, 0.16);
}

* { 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: 16.5px;
  line-height: 1.65;
  -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(--yangtze); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }

/* ─── Topbar ─────────────────────────────── */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, 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: 64px;
}
.brand {
  display: flex; align-items: center; gap: 12px;
  font-family: var(--display); font-size: 20px; letter-spacing: 0.005em;
  color: var(--ink); font-style: italic;
}
.brand-mark {
  width: 28px; height: 28px; flex: 0 0 auto;
  border-radius: 999px;
  background:
    conic-gradient(from 0deg,
      var(--beijing) 0 25%,
      var(--yangtze) 25% 50%,
      var(--pearl) 50% 75%,
      var(--hk) 75% 100%);
  position: relative;
}
.brand-mark::after {
  content: ""; position: absolute; inset: 7px; border-radius: 999px;
  background: var(--bg);
}
.brand small {
  font-family: var(--mono); font-size: 10.5px; color: var(--ink-mute);
  letter-spacing: 0.16em; 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: 11.5px;
  letter-spacing: 0.1em; text-transform: uppercase;
}
.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; letter-spacing: 0.06em;
  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: 940px) {
  .nav { display: none; }
}

/* ─── Hero ─────────────────────────────── */
.hero {
  padding: 96px 0 80px;
  border-bottom: 1px solid var(--border);
  position: relative; overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(40% 60% at 80% 20%, rgba(58, 155, 155, 0.10), transparent 60%),
    radial-gradient(40% 60% at 15% 70%, rgba(214, 84, 132, 0.09), transparent 60%),
    radial-gradient(40% 60% at 60% 95%, rgba(212, 160, 23, 0.08), transparent 60%);
  pointer-events: none;
}
.hero-inner { position: relative; }
.hero-eyebrow {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--ink-dim); margin-bottom: 26px;
}
.hero-eyebrow .dot {
  display: inline-block; width: 8px; height: 8px; border-radius: 50%;
  margin-right: 5px; vertical-align: middle;
}
.hero h1 {
  font-family: var(--display); font-weight: 400;
  font-size: clamp(44px, 7.2vw, 92px);
  line-height: 1.04; letter-spacing: -0.012em;
  margin: 0 0 22px; color: var(--ink);
}
.hero h1 em {
  font-style: italic; color: var(--beijing);
}
.hero h1 em.y { color: var(--yangtze); }
.hero h1 em.p { color: var(--pearl); }
.hero h1 em.h { color: var(--hk); }

.hero-sub {
  font-size: 18px; color: var(--ink-dim); max-width: 780px;
  margin: 0 0 32px; line-height: 1.65;
}
.hero-meta {
  display: flex; flex-wrap: wrap; gap: 20px;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--ink-mute);
}
.hero-meta span::before { content: "◇ "; color: var(--yangtze); }

/* ─── Section ─────────────────────────────── */
section.module {
  padding: 80px 0; border-bottom: 1px solid var(--border);
}
.section-head {
  display: grid; grid-template-columns: 240px 1fr; gap: 36px;
  margin-bottom: 36px; align-items: start;
}
.section-tag {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.22em;
  text-transform: uppercase; color: var(--ink-dim);
  border-top: 1px solid var(--border-strong); padding-top: 8px;
}
.section-head h2 {
  font-family: var(--display); font-weight: 400; font-style: italic;
  font-size: clamp(30px, 4vw, 48px); margin: 0;
  line-height: 1.05; color: var(--ink); letter-spacing: -0.01em;
}
.section-lede {
  margin-top: 16px; color: var(--ink-dim); max-width: 820px;
  font-size: 16.5px;
}
@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: 24px;
  box-shadow: var(--shadow);
}
.map-svg-wrap { width: 100%; overflow: hidden; border-radius: 8px; }
.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);
  letter-spacing: 0.04em;
}
.map-legend .swatch {
  display: inline-block; width: 12px; height: 12px; border-radius: 3px;
  vertical-align: middle; margin-right: 6px;
}

/* ─── Region cards ─────────────────────────────── */
.region-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 18px;
}
.region {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 24px 24px 20px;
  position: relative; overflow: hidden;
  transition: border-color 0.18s, transform 0.18s;
}
.region::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: var(--accent, var(--neutral));
}
.region:hover { border-color: var(--border-strong); transform: translateY(-2px); }
.region.beijing { --accent: var(--beijing); }
.region.yangtze { --accent: var(--yangtze); }
.region.pearl   { --accent: var(--pearl); }
.region.hk      { --accent: var(--hk); }
.region.shanghai { --accent: var(--yangtze); }

.region-tag {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.22em;
  color: var(--accent, var(--neutral)); text-transform: uppercase; margin-bottom: 8px;
}
.region h3 {
  font-family: var(--display); font-weight: 400; font-size: 24px;
  margin: 0 0 8px; color: var(--ink); line-height: 1.2;
}
.region .sub {
  font-family: var(--mono); font-size: 11px; color: var(--ink-mute);
  margin-bottom: 12px;
}
.region p { color: var(--ink-dim); font-size: 14.5px; line-height: 1.65; margin: 0 0 8px; }
.region .stat-row {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 6px;
  margin-top: 14px; font-family: var(--mono); font-size: 10.5px; color: var(--ink-mute);
}
.region .stat-row span.v { display: block; color: var(--ink); font-size: 14px; margin-top: 2px; font-family: var(--display); }

/* ─── 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: 14px 16px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.comp-table th {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--ink-dim);
  background: var(--surface-2);
}
.comp-table tr:last-child td { border-bottom: 0; }
.comp-table td:first-child { font-weight: 500; color: var(--ink); font-family: var(--display); font-size: 16px; font-style: italic; }
.comp-table .col-beijing { color: var(--beijing); }
.comp-table .col-yangtze { color: var(--yangtze); }
.comp-table .col-pearl   { color: var(--pearl); }
.comp-table .col-hk      { color: var(--hk); }

/* ─── Card row (generic) ─────────────────────────────── */
.card-row {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 18px;
}
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 24px;
}
.card .kicker {
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--ink-dim); margin-bottom: 10px;
}
.card h3 {
  font-family: var(--display); font-style: italic; font-weight: 400;
  font-size: 24px; margin: 0 0 8px; color: var(--ink); line-height: 1.18;
}
.card p { color: var(--ink-dim); font-size: 14.5px; line-height: 1.65; margin: 0 0 8px; }

/* ─── Flow viz ─────────────────────────────── */
.flow-viz {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 22px;
}
.flow-viz svg { width: 100%; height: auto; display: block; }

/* ─── Bar chart row ─────────────────────────────── */
.bar-rows {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 24px;
}
.bar-rows .row {
  display: grid; grid-template-columns: 200px 1fr 80px;
  gap: 12px; align-items: center;
  font-family: var(--mono); font-size: 12px; color: var(--ink-dim);
  margin-bottom: 12px;
}
.bar-rows .row .label .swatch {
  display: inline-block; width: 8px; height: 8px; border-radius: 2px;
  margin-right: 6px; vertical-align: middle;
}
.bar-rows .row .meter {
  height: 12px; border-radius: 4px;
  background: var(--surface-2); position: relative; overflow: hidden;
}
.bar-rows .row .meter > i {
  position: absolute; left: 0; top: 0; bottom: 0;
  background: var(--bar-color, var(--neutral));
}
.bar-rows .row .v {
  font-family: var(--display); font-size: 16px; color: var(--ink); text-align: right;
}

/* ─── Simulator ─────────────────────────────── */
.sim-shell {
  display: grid; grid-template-columns: 320px 1fr; gap: 24px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 26px;
}
@media (max-width: 880px) { .sim-shell { grid-template-columns: 1fr; } }
.sim-shell h3 {
  font-family: var(--display); font-style: italic; font-weight: 400;
  font-size: 22px; margin: 0 0 14px;
}
.sim-controls label {
  display: block; font-family: var(--mono); font-size: 11px;
  letter-spacing: 0.12em; color: var(--ink-mute); text-transform: uppercase;
  margin-bottom: 6px; margin-top: 14px;
}
.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: 4px;
  padding: 8px 10px; 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: 10px; align-items: center;
  font-family: var(--mono); font-size: 12px; color: var(--ink-dim);
}
.sim-output .sbar .meter {
  height: 10px; 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(--yangtze), var(--hk));
  transition: width 0.4s;
}
.sim-output .sbar .v { color: var(--ink); text-align: right; font-family: var(--display); font-size: 16px; }
.sim-readout {
  font-family: var(--mono); font-size: 12.5px; color: var(--ink-dim);
  border: 1px dashed var(--border-strong);
  border-radius: 6px; padding: 14px 16px; margin-top: 8px;
  line-height: 1.65;
}

/* ─── AI ─────────────────────────────── */
.ai-shell {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 26px;
}
.ai-prompts { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.ai-prompt {
  font-family: var(--mono); font-size: 11.5px; letter-spacing: 0.04em;
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: 999px; padding: 8px 14px; color: var(--ink-dim);
  cursor: pointer; transition: all 0.16s;
}
.ai-prompt:hover { color: var(--ink); border-color: var(--yangtze); }
.ai-input-row { display: flex; gap: 8px; }
.ai-input-row input {
  flex: 1; background: var(--surface-2); color: var(--ink);
  border: 1px solid var(--border-strong); border-radius: 4px;
  padding: 11px 14px; font-family: var(--body); font-size: 14.5px;
}
.ai-input-row button {
  background: var(--yangtze); color: var(--bg); border: 0;
  padding: 11px 22px; font-family: var(--mono); font-size: 12px;
  letter-spacing: 0.14em; text-transform: uppercase;
  border-radius: 4px; cursor: pointer; font-weight: 700;
}
.ai-input-row button:hover { background: var(--hk); }
.ai-output {
  margin-top: 18px; min-height: 80px;
  font-size: 15px; line-height: 1.75; color: var(--ink-dim);
  border-top: 1px solid var(--border); padding-top: 16px;
}
.ai-output strong { color: var(--ink); }
.ai-output em {
  font-style: normal; color: var(--yangtze); font-family: var(--mono);
  font-size: 12.5px; letter-spacing: 0.06em;
}
.ai-output p { margin: 0 0 12px; }

/* ─── Guardrails ─────────────────────────────── */
.guardrails {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 26px;
  border-left: 3px solid var(--beijing);
}
.guardrails h3 { font-family: var(--display); font-style: italic; font-weight: 400; margin: 0 0 12px; font-size: 24px; }
.guardrails ul { margin: 0; padding-left: 20px; }
.guardrails li { color: var(--ink-dim); margin-bottom: 10px; font-size: 14.5px; }

/* ─── Footer ─────────────────────────────── */
footer {
  padding: 60px 0 50px;
  font-family: var(--mono); font-size: 12px; color: var(--ink-mute);
  letter-spacing: 0.04em;
}
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: 18px; flex-wrap: wrap; }

/* ─── Util ─────────────────────────────── */
.mono { font-family: var(--mono); }
.dim { color: var(--ink-dim); }
.tag-beijing { color: var(--beijing); }
.tag-yangtze { color: var(--yangtze); }
.tag-pearl   { color: var(--pearl); }
.tag-hk      { color: var(--hk); }