:root {
  color-scheme: light;
  --bg: #f3efe6;
  --panel: #fffdf8;
  --ink: #192430;
  --muted: #59687a;
  --line: #d8d0c2;
  --accent: #234e70;
  --accent-2: #a85d30;
  --soft: #e7eef5;
  --soft-2: #f4e7dd;
  --shadow: 0 18px 45px rgba(27, 34, 43, 0.08);
}
html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0f1419;
  --panel: #17212b;
  --ink: #eef3f8;
  --muted: #a7b6c7;
  --line: #2d3945;
  --accent: #8dc0eb;
  --accent-2: #efb18a;
  --soft: #1e2d39;
  --soft-2: #39261c;
  --shadow: 0 18px 45px rgba(0, 0, 0, 0.24);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "PingFang SC", "Noto Serif CJK SC", "Songti SC", -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.72;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(168,93,48,.08), transparent 28%),
    radial-gradient(circle at top right, rgba(35,78,112,.08), transparent 26%),
    var(--bg);
}
a { color: inherit; }
img { max-width: 100%; display: block; }
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 24px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(14px);
}
.brand {
  font-weight: 800;
  text-decoration: none;
  letter-spacing: .03em;
}
nav {
  display: flex;
  gap: 8px;
  margin-left: auto;
}
nav a, .tag, .button {
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 7px 12px;
  background: var(--panel);
}
nav a.active, .tag:hover, .button:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.icon-button {
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel);
  color: var(--ink);
  cursor: pointer;
}
main {
  max-width: 1240px;
  margin: 0 auto;
  padding: 28px 22px 72px;
}
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(300px, .75fr);
  gap: 22px;
  align-items: end;
  padding: 20px 0 22px;
}
.hero h1 {
  margin: 0 0 14px;
  font-size: clamp(34px, 5vw, 62px);
  line-height: 1.08;
}
.hero p {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 18px;
}
.hero-panel {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: linear-gradient(160deg, var(--panel), color-mix(in srgb, var(--soft) 28%, var(--panel)));
  box-shadow: var(--shadow);
}
.hero-grid, .grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 14px;
}
.metric {
  border-left: 4px solid var(--accent);
  padding: 16px;
  border-radius: 14px;
  background: var(--panel);
  box-shadow: var(--shadow);
}
.metric strong {
  display: block;
  font-size: 28px;
  margin-bottom: 4px;
}
.section-title {
  margin: 34px 0 12px;
  font-size: 26px;
}
.card {
  margin: 16px 0;
  padding: 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: var(--shadow);
}
.card h2, .card h3 {
  margin-top: 0;
  line-height: 1.26;
}
.chapter-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.eyebrow {
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.snippet {
  color: var(--muted);
}
.tag-row, .route, .chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.chapter-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 18px;
  align-items: start;
}
.side {
  position: sticky;
  top: 76px;
}
.split {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}
.deep-card {
  padding: 16px 0;
  border-top: 1px solid var(--line);
}
.deep-card:first-child {
  border-top: 0;
  padding-top: 0;
}
.plate-thumb {
  display: block;
  min-height: 120px;
  border: 1px solid var(--line);
  border-radius: 16px;
  overflow: hidden;
  background: color-mix(in srgb, var(--soft) 38%, var(--panel));
}
.plate-thumb img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}
.plate-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
}
.plate-panel {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, .9fr);
  gap: 18px;
}
.plate-image {
  padding: 18px;
  border-radius: 20px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, color-mix(in srgb, var(--soft) 22%, var(--panel)), var(--panel));
  box-shadow: var(--shadow);
}
.note-box {
  padding: 14px 16px;
  border-left: 4px solid var(--accent-2);
  background: color-mix(in srgb, var(--soft-2) 45%, var(--panel));
  border-radius: 14px;
}
.toc-list, .plate-group-list {
  display: grid;
  gap: 10px;
}
.toc-item, .plate-group-item {
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--panel);
  text-decoration: none;
}
.toc-item:hover, .plate-group-item:hover {
  border-color: var(--accent);
}
details {
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 12px 14px;
  background: color-mix(in srgb, var(--soft) 16%, var(--panel));
}
summary {
  cursor: pointer;
  font-weight: 700;
}
.footer-nav {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 20px;
}
.footer-nav a {
  flex: 1 1 0;
  text-align: center;
}
@media (max-width: 980px) {
  .hero, .chapter-layout, .plate-panel {
    grid-template-columns: 1fr;
  }
  .side {
    position: static;
  }
}
@media (max-width: 700px) {
  nav {
    display: none;
  }
  main {
    padding: 22px 16px 56px;
  }
  .split {
    grid-template-columns: 1fr;
  }
}