:root {
  --bg: #eef1ec;
  --paper: #fffdf9;
  --ink: #1f2b26;
  --muted: #5d6a64;
  --line: #d1d9d2;
  --accent: #8b5d39;
  --accent-soft: #efe3d4;
  --shadow: 0 18px 46px rgba(24, 42, 28, 0.08);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(139, 93, 57, 0.16), transparent 24%),
    linear-gradient(180deg, #f8f4ec 0%, var(--bg) 100%);
  font-family: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", sans-serif;
}
a { color: inherit; text-decoration: none; }
.site-shell { max-width: 1360px; margin: 0 auto; padding: 0 20px 48px; }
.site-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  padding: 20px 0 14px;
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(248, 244, 236, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(209, 217, 210, 0.74);
}
.brand {
  font-family: "Source Han Serif SC", "Noto Serif SC", "Songti SC", serif;
  font-size: 1.14rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.top-nav { display: flex; gap: 16px; flex-wrap: wrap; color: var(--muted); font-size: 0.94rem; }
.page { padding-top: 18px; }
.path-panel {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
  padding: 10px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.66);
  color: var(--muted);
  font-size: 0.92rem;
}
.hero, .detail-hero {
  margin-top: 22px;
  padding: 34px;
  border-radius: 30px;
  border: 1px solid var(--line);
  background: rgba(255, 253, 249, 0.92);
  box-shadow: var(--shadow);
  display: grid;
  gap: 28px;
}
.hero { grid-template-columns: 1.55fr 0.8fr; }
.detail-hero { grid-template-columns: 1.3fr 0.8fr; }
.eyebrow {
  display: inline-block;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.hero h1, .detail-copy h1, .section-heading h1, .section-heading h2 {
  margin: 14px 0 12px;
  font-family: "Source Han Serif SC", "Noto Serif SC", "Songti SC", serif;
  line-height: 1.16;
}
.hero-summary, .thesis { font-size: 1.08rem; line-height: 1.82; color: #294134; }
.hero-stats {
  margin-top: 26px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}
.hero-stats div, .hero-note, .panel, .side-card, .path-card {
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
}
.hero-stats div { padding: 18px; }
.hero-stats strong {
  display: block;
  font-size: 1.82rem;
  font-family: "Source Han Serif SC", "Noto Serif SC", "Songti SC", serif;
}
.hero-stats span { color: var(--muted); }
.hero-note { padding: 20px; }
.hero-note ul, .panel ul, .panel ol { padding-left: 1.2rem; line-height: 1.8; }
.section { margin-top: 34px; }
.section-heading { display: flex; flex-direction: column; gap: 6px; margin-bottom: 18px; }
.section-heading p { margin: 0; color: var(--muted); line-height: 1.72; }
.section-heading.split { flex-direction: row; align-items: end; justify-content: space-between; gap: 18px; }
.search-wrap input {
  width: min(360px, 72vw);
  padding: 14px 16px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
  font-size: 1rem;
}
.chapter-grid, .concept-grid, .plate-grid, .route-grid { display: grid; gap: 18px; }
.chapter-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.concept-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.plate-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card, .plate-card {
  padding: 22px;
  border-radius: 24px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.86);
  box-shadow: var(--shadow);
  transition: transform 160ms ease, border-color 160ms ease, box-shadow 160ms ease;
}
.card:hover, .plate-card:hover, .path-card:hover, .thumb-button:hover { transform: translateY(-2px); border-color: rgba(139, 93, 57, 0.35); }
.card-kicker, .plate-meta span { color: var(--accent); font-size: 0.84rem; }
.card h3, .plate-meta h3 { margin: 10px 0; font-size: 1.12rem; line-height: 1.42; }
.card p, .plate-meta p { margin: 0; color: var(--muted); line-height: 1.75; }
.plate-card {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 18px;
  align-items: center;
}
.plate-thumb-shell {
  aspect-ratio: 4 / 3;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #fbf8f2 0%, #eef2ec 100%);
}
.plate-thumb { width: 100%; height: 100%; object-fit: contain; border-radius: 12px; background: #fbfaf6; }
.detail-grid {
  margin-top: 24px;
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) 320px;
  gap: 22px;
}
.main-column, .rail-column { display: flex; flex-direction: column; gap: 18px; }
.panel, .side-card { padding: 22px; }
.panel h2, .side-card h2 { margin: 0 0 14px; font-size: 1.08rem; }
.panel h3 { margin: 0 0 8px; font-size: 1rem; }
.panel p, .side-card p, .panel li { color: var(--muted); line-height: 1.82; }
.route-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.route-item {
  padding: 16px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #fffef9 0%, #f2f5ef 100%);
}
.route-item strong { display: block; margin-bottom: 8px; }
.route-item span { display: block; color: var(--muted); line-height: 1.7; font-size: 0.94rem; }
.deep-grid, .mini-plate-grid, .path-stack, .group-stack, .viewer-strip, .concept-summary-grid { display: grid; gap: 14px; }
.deep-card {
  padding: 18px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #fffef9 0%, #f3f6f1 100%);
}
.mini-plate {
  display: grid;
  grid-template-columns: 88px 1fr;
  gap: 12px;
  align-items: center;
  padding: 10px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.76);
}
.mini-plate span { font-size: 0.95rem; line-height: 1.52; }
.plate-reader {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 18px;
  border-radius: 24px;
  background: linear-gradient(180deg, #faf8f2 0%, #eef3ed 100%);
  border: 1px solid var(--line);
}
.plate-full { max-width: 100%; max-height: 72vh; object-fit: contain; border-radius: 14px; }
.thumb-button {
  display: grid;
  grid-template-columns: 74px 1fr;
  gap: 10px;
  align-items: center;
  width: 100%;
  padding: 10px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.76);
  cursor: pointer;
  text-align: left;
}
.thumb-button img {
  width: 74px;
  height: 56px;
  object-fit: contain;
  border-radius: 10px;
  background: #fbfaf6;
  border: 1px solid rgba(209, 217, 210, 0.88);
}
.thumb-button span { color: var(--muted); line-height: 1.5; font-size: 0.93rem; }
.thumb-button.is-active { border-color: rgba(139, 93, 57, 0.56); background: rgba(239, 227, 212, 0.5); }
.viewer-caption { margin: 12px 0 0; color: var(--muted); line-height: 1.72; }
.answer-toggle, .learning-path a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 16px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.84);
  color: var(--accent);
  cursor: pointer;
  font: inherit;
}
.answer-panel {
  display: none;
  margin-top: 14px;
  padding: 16px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line);
}
.answer-panel.is-open { display: block; }
.learning-path { display: flex; flex-wrap: wrap; gap: 14px; }
.path-card {
  display: block;
  padding: 16px 18px;
}
.path-card strong { display: block; margin-bottom: 8px; }
.path-card span, .concept-summary-card span { display: block; color: var(--muted); line-height: 1.66; }
.plate-path-group {
  padding: 16px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #fffef8 0%, #f3f6f0 100%);
}
.plate-path-group h3 { margin: 0 0 12px; }
.concept-summary-card {
  padding: 14px 16px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.8);
}
.glossary-table {
  overflow: auto;
  border-radius: 22px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.86);
  box-shadow: var(--shadow);
}
table { width: 100%; border-collapse: collapse; }
th, td { padding: 16px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: rgba(139, 93, 57, 0.08); }
.is-hidden { display: none !important; }
@media (max-width: 980px) {
  .hero, .detail-hero, .detail-grid, .chapter-grid, .concept-grid, .plate-grid, .route-grid { grid-template-columns: 1fr; }
  .plate-card, .mini-plate, .thumb-button { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .section-heading.split { flex-direction: column; align-items: stretch; }
}