/* ========================================
   gongshangzheng.github.io Theme — Auto-generated from modules
   Do not edit hugo-theme.css directly — edit modules/*.css instead
   ======================================== */


/* ===========================
   CSS Variables — Light (default)
   =========================== */
:root {
  --bg-body: #faf8f5;
  --bg-block: #f0ece6;
  --bg-code: #f4f1ec;
  --bg-menu: #e8e2d9;
  --bg-menu-hover: #ddd6cb;
  --bg-nav: rgba(250, 248, 245, 0.95);
  --bg-card: #ffffff;
  --bg-card-hover: #f5f0e8;

  --text-color: #2c2418;
  --text-muted: #6b5e4f;
  --text-heading: #3a2e1e;

  --border-color: #d4ccc0;
  --border-light: #e4ddd3;

  --link-color: #8b5e34;
  --link-hover: #a67342;
  --link-underline: rgba(139, 94, 52, 0.42);
  --link-bg-hover: rgba(139, 94, 52, 0.08);

  --shadow-soft: 0 2px 8px rgba(44, 36, 24, 0.06);

  --h1-color: #8b4513;
  --h2-color: #a0622e;
  --h3-color: #6b5e4f;
  --h4-color: #7a6b58;

  --accent: #8b4513;
  --accent-gold: #d4a017;
  --accent-blue: #3287d0;
  --accent-red: #b31b1b;

  --scrollbar-track: var(--bg-body);
  --scrollbar-thumb: var(--border-color);
  --scrollbar-thumb-hover: #b8ad9e;

  --hero-grad: linear-gradient(135deg, #3a2e1e, #5c4a32, #8b6b3e);
  --hero-text: #faf8f5;
  --hero-sub: rgba(250, 248, 245, 0.75);

  --tbl-head-bg: #f0ece6;
  --tbl-head-fg: #3a2e1e;

  /* Course notes components */
  --conn-title-color: #3a2e1e;
  --geom-box-title: #7c3aed;
  --app-box-title: #c2410c;
}

/* ===========================
   Dark mode — html.dark
   =========================== */
html.dark {
  --bg-body: #1c1914;
  --bg-block: #2a241d;
  --bg-code: #221e18;
  --bg-menu: #2a241d;
  --bg-menu-hover: #352e25;
  --bg-nav: rgba(28, 25, 20, 0.95);
  --bg-card: #242019;
  --bg-card-hover: #2e2820;

  --text-color: #d8cfc2;
  --text-muted: #a09585;
  --text-heading: #e4dcd0;

  --border-color: #3d362c;
  --border-light: #2f2920;

  --link-color: #d4a76a;
  --link-hover: #f0c98a;
  --link-underline: rgba(212, 167, 106, 0.5);
  --link-bg-hover: rgba(212, 167, 106, 0.12);

  --shadow-soft: 0 2px 8px rgba(0, 0, 0, 0.2);

  --h1-color: #e0a050;
  --h2-color: #d4a76a;
  --h3-color: #c0b09a;
  --h4-color: #a89e8e;

  --accent: #e0a050;
  --accent-gold: #f0c040;
  --accent-blue: #60a5fa;
  --accent-red: #ef4444;

  --scrollbar-thumb: var(--border-color);
  --scrollbar-thumb-hover: #5a4f42;

  --hero-grad: linear-gradient(135deg, #1c1914, #2a241d, #3a3020);
  --hero-text: #faf8f5;
  --hero-sub: rgba(250, 248, 245, 0.7);

  --tbl-head-bg: #2a241d;
  --tbl-head-fg: #d4a76a;

  /* Course notes components */
  --conn-title-color: #e4dcd0;
  --geom-box-title: #a78bfa;
  --app-box-title: #fb923c;
}


/* ===========================
   Base
   =========================== */
* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background-color: var(--bg-body);
  color: var(--text-color);
  font-family: 'Zhuque Fangsong (technical preview)', system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}


/* ===========================
   Typography
   =========================== */
h1, h2, h3, h4, h5, h6 {
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  color: var(--text-heading);
  line-height: 1.4;
}

h1 { font-size: 1.75rem; font-weight: 700; color: var(--h1-color); }
h2 { font-size: 1.4rem; font-weight: 600; color: var(--h2-color); }
h3 { font-size: 1.2rem; font-weight: 600; color: var(--h3-color); }
h4 { font-size: 1.05rem; font-weight: 500; color: var(--h4-color); }

/* Content area heading spacing */
.wrap h1,
.main-content h1 {
  margin-top: 2em;
  margin-bottom: 0.8em;
  padding-bottom: 0.4em;
  border-bottom: 2px solid var(--accent);
}
.wrap h2,
.main-content h2 {
  margin-top: 1.8em;
  margin-bottom: 0.6em;
  padding-bottom: 0.3em;
  border-bottom: 1px solid var(--border-color);
}
.wrap h3,
.main-content h3 {
  margin-top: 1.4em;
  margin-bottom: 0.5em;
}
.wrap h4,
.main-content h4 {
  margin-top: 1.2em;
  margin-bottom: 0.4em;
}
/* First heading in content area should not have top margin */
.wrap > h1:first-child,
.wrap > h2:first-child,
.wrap > h3:first-child,
.main-content > h1:first-child,
.main-content > h2:first-child,
.main-content > h3:first-child {
  margin-top: 0;
}

a {
  color: var(--link-color);
  text-decoration-line: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  text-decoration-color: var(--link-underline);
  text-decoration-skip-ink: auto;
  transition: color 0.18s ease, text-decoration-color 0.18s ease, background-color 0.18s ease, box-shadow 0.18s ease;
}
a:hover,
a:focus-visible {
  color: var(--link-hover);
  text-decoration-color: currentColor;
  text-decoration-thickness: 1.5px;
}
a:focus-visible {
  outline: 2px solid var(--accent-blue);
  outline-offset: 3px;
  border-radius: 3px;
}
.nav-brand,
.nav-links li a,
.nav-toggle-btn,
.nav-hamburger,
.nav-toc-btn,
.nav-music-btn,
#toc-nav a,
#category-nav a,
.mobile-toc-nav li a,
.hero-inner a {
  text-decoration: none;
}

strong { font-weight: 700; }

/* 正文链接：与普通文字明显区分，保留导航/卡片等组件自己的样式 */
.main-content p a,
.main-content li a,
.main-content blockquote a,
.main-content td a,
.main-content figcaption a,
.wrap p a,
.wrap li a,
.wrap blockquote a,
.wrap td a,
.wrap figcaption a {
  font-weight: 600;
  color: var(--link-color);
  text-decoration-line: underline;
  text-decoration-thickness: 1.2px;
  text-underline-offset: 0.2em;
  text-decoration-color: var(--link-underline);
  border-radius: 3px;
  padding: 0 0.04em;
}
.main-content p a:hover,
.main-content li a:hover,
.main-content blockquote a:hover,
.main-content td a:hover,
.main-content figcaption a:hover,
.wrap p a:hover,
.wrap li a:hover,
.wrap blockquote a:hover,
.wrap td a:hover,
.wrap figcaption a:hover {
  color: var(--link-hover);
  background: var(--link-bg-hover);
  text-decoration-color: currentColor;
  text-decoration-thickness: 1.6px;
  box-shadow: inset 0 -0.12em 0 var(--link-bg-hover);
}

code {
  background: var(--bg-code);
  padding: 2px 5px;
  border-radius: 3px;
  font-size: 0.9em;
  font-weight: 500;
}

pre {
  background: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 1em;
  overflow-x: auto;
  line-height: 1.5;
}
pre code { background: none; padding: 0; }

blockquote {
  background: var(--bg-block);
  border-left: 4px solid var(--link-color);
  margin: 1.2em 0;
  padding: 0.8em 1.2em;
  border-radius: 0 4px 4px 0;
}


/* Highlight mark */
mark {
  background: rgba(168, 115, 66, 0.25);
  color: var(--text-color);
  padding: 1px 4px;
  border-radius: 2px;
}

/* ===========================
   Reusable article components
   =========================== */
.wrap .info-box,
.main-content .info-box,
.wrap .example-box,
.main-content .example-box,
.wrap .def-box,
.main-content .def-box,
.wrap .theorem-box,
.main-content .theorem-box,
.wrap .sources,
.main-content .sources,
.wrap .chapter-nav,
.main-content .chapter-nav,
.wrap .review-box,
.main-content .review-box {
  border-radius: 12px;
  padding: 1.15rem 1.3rem;
  margin: 1.25rem 0;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-soft);
}

.wrap .info-box,
.main-content .info-box {
  background: color-mix(in srgb, var(--accent-gold) 10%, var(--bg-card));
  border-color: color-mix(in srgb, var(--accent-gold) 30%, var(--border-color));
}
.wrap .info-box h3,
.main-content .info-box h3 {
  color: color-mix(in srgb, var(--accent-gold) 75%, var(--text-heading));
  margin-top: 0;
  margin-bottom: 0.7rem;
}
.wrap .info-box p,
.wrap .info-box li,
.main-content .info-box p,
.main-content .info-box li {
  color: var(--text-color);
}

.wrap .example-box,
.main-content .example-box {
  background: color-mix(in srgb, var(--accent-blue) 10%, var(--bg-card));
  border-color: color-mix(in srgb, var(--accent-blue) 30%, var(--border-color));
}
.wrap .example-box h3,
.main-content .example-box h3 {
  color: color-mix(in srgb, var(--accent-blue) 82%, var(--text-heading));
  margin-top: 0;
  margin-bottom: 0.8rem;
}
.wrap .example-box p,
.wrap .example-box li,
.main-content .example-box p,
.main-content .example-box li {
  color: var(--text-color);
}

.wrap .def-box,
.main-content .def-box {
  background: color-mix(in srgb, var(--accent-blue) 7%, var(--bg-card));
  border-color: color-mix(in srgb, var(--accent-blue) 24%, var(--border-color));
}
.wrap .def-box h3,
.main-content .def-box h3 {
  color: color-mix(in srgb, var(--accent-blue) 88%, var(--text-heading));
  margin-top: 0;
  margin-bottom: 0.7rem;
}
.wrap .def-box p,
.wrap .def-box li,
.main-content .def-box p,
.main-content .def-box li {
  color: var(--text-color);
}

.wrap .theorem-box,
.main-content .theorem-box {
  background: color-mix(in srgb, #10b981 9%, var(--bg-card));
  border-color: color-mix(in srgb, #10b981 28%, var(--border-color));
}
.wrap .theorem-box h3,
.main-content .theorem-box h3 {
  color: color-mix(in srgb, #10b981 78%, var(--text-heading));
  margin-top: 0;
  margin-bottom: 0.7rem;
}
.wrap .theorem-box p,
.wrap .theorem-box li,
.main-content .theorem-box p,
.main-content .theorem-box li {
  color: var(--text-color);
}

.wrap .callout,
.main-content .callout {
  background: color-mix(in srgb, var(--accent-red) 10%, var(--bg-card));
  border: 1px solid color-mix(in srgb, var(--accent-red) 30%, var(--border-color));
  border-left: 4px solid var(--accent-red);
  border-radius: 10px;
  padding: 0.9rem 1rem;
  margin: 1rem 0;
  color: var(--text-color);
}
.wrap .callout strong,
.main-content .callout strong {
  color: color-mix(in srgb, var(--accent-red) 72%, var(--text-heading));
}

/* conn-card — used by course chapter navigation */
.conn-card .conn-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--conn-title-color);
  margin-bottom: 0.4rem;
}

/* chapter-nav — 上一章 / 下一章导航卡片 */
.wrap .chapter-nav,
.main-content .chapter-nav {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(0, 1fr));
  gap: 0.9rem;
  background: var(--bg-card);
}
.wrap .chapter-nav .nav-card,
.main-content .chapter-nav .nav-card {
  display: block;
  min-height: 100%;
  padding: 1rem 1.05rem;
  border: 1px solid var(--border-light);
  border-radius: 10px;
  background: color-mix(in srgb, var(--bg-card) 85%, var(--bg-block));
  text-decoration: none;
  transition: transform 0.18s ease, border-color 0.18s ease, background-color 0.18s ease, box-shadow 0.18s ease;
}
.wrap .chapter-nav .nav-card:hover,
.main-content .chapter-nav .nav-card:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--accent) 35%, var(--border-color));
  background: color-mix(in srgb, var(--accent) 8%, var(--bg-card));
  box-shadow: var(--shadow-soft);
}
.wrap .chapter-nav .nav-label,
.main-content .chapter-nav .nav-label {
  display: block;
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}
.wrap .chapter-nav .nav-title,
.main-content .chapter-nav .nav-title {
  display: block;
  font-weight: 700;
  color: var(--text-heading);
}
.wrap .chapter-nav .nav-card.current,
.main-content .chapter-nav .nav-card.current {
  border-style: dashed;
}
@media (max-width: 768px) {
  .wrap .chapter-nav,
  .main-content .chapter-nav {
    grid-template-columns: 1fr;
  }
}


/* ===========================
   Scrollbar
   =========================== */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--scrollbar-track); }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--scrollbar-thumb-hover); }

/* ===========================
   Nav
   =========================== */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 900;
  background: var(--bg-nav);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-light);
  padding: 0 1.5rem;
}

.nav-inner {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  overflow: hidden;
  min-width: 0;
}

.nav-brand {
  display: flex;
  align-items: baseline;
  gap: 0.4rem;
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 1;
  min-width: 0;
  overflow: hidden;
}
.brand-mark {
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-heading);
  letter-spacing: -0.02em;
  flex-shrink: 0;
  display: flex;
  align-items: center;
}
html.dark .brand-mark svg circle,
html.dark .brand-mark svg rect {
  fill: #d4a76a;
}
.brand-sub {
  font-family: 'Zhuque Fangsong (technical preview)', system-ui, sans-serif;
  font-size: 0.78rem;
  color: var(--text-muted);
  letter-spacing: 0.01em;
  transition: opacity 0.2s;
  overflow: hidden;
  text-overflow: ellipsis;
}
.nav-brand:hover .brand-mark { color: var(--link-hover); }
.nav-brand:hover .brand-sub { color: var(--text-color); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links li a {
  display: block;
  padding: 0.4rem 0.75rem;
  color: var(--text-color);
  text-decoration: none;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  font-size: 0.9rem;
  border-radius: 6px;
  transition: background 0.2s, color 0.2s;
}
.nav-links li a:hover {
  background: var(--bg-menu-hover);
  color: var(--link-hover);
}

.nav-toggle-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background: var(--bg-block);
  cursor: pointer;
  font-size: 18px;
  transition: background 0.2s, border-color 0.2s;
}
.nav-toggle-btn:hover { background: var(--bg-menu-hover); }

.nav-right-btns {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-music-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background: var(--bg-block);
  cursor: pointer;
  font-size: 18px;
  color: var(--text-color);
  transition: background 0.2s, border-color 0.2s;
}
.nav-music-btn:hover { background: var(--bg-menu-hover); }
.nav-music-btn.playing { color: var(--accent-blue); }

.nav-hamburger {
  display: none;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background: var(--bg-block);
  cursor: pointer;
  color: var(--text-color);
}
.nav-hamburger svg { width: 22px; height: 22px; }

@media (max-width: 768px) {
  .nav-hamburger { display: flex; }
  .nav-right-btns {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-shrink: 0;
  }
  .nav-links {
    display: none;
    position: absolute;
    top: 56px; left: 0; right: 0;
    flex-direction: column;
    background: var(--bg-nav);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border-color);
    padding: 0.5rem 0;
    gap: 0;
  }
  .nav-links.is-open { display: flex; }
  .nav-links li a {
    padding: 0.75rem 1.5rem;
    border-radius: 0;
    font-size: 1rem;
  }
}

/* 极窄屏幕：自适应 nav-brand */
@media (max-width: 480px) {
  .nav-inner { gap: 0.25rem; padding: 0 0.5rem; }
  .nav-music-btn, .nav-hamburger, .nav-toggle-btn { width: 44px; height: 44px; font-size: 15px; }
  .nav-toc-btn { width: 44px; height: 44px; }
}

/* ===========================
   Search Dropdown
   =========================== */
.search-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 950;
  background: rgba(0, 0, 0, 0.3);
  opacity: 0;
  transition: opacity 0.2s ease;
}
.search-overlay.is-open {
  display: block;
  opacity: 1;
}
html.dark .search-overlay {
  background: rgba(0, 0, 0, 0.5);
}

.search-dropdown {
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  z-index: 960;
  width: 100%;
  max-width: 640px;
  padding: 70px 1rem 0;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.2s ease, top 0.2s ease;
}
.search-dropdown.is-open {
  pointer-events: auto;
  opacity: 1;
}
.search-dropdown-inner {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
  overflow: hidden;
}
html.dark .search-dropdown-inner {
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

.search-input-wrap {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-light);
}
.search-input-wrap svg {
  flex-shrink: 0;
  color: var(--text-muted);
}
#search-input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  color: var(--text-color);
  font-family: inherit;
  font-size: 1rem;
}
#search-input::placeholder {
  color: var(--text-muted);
}
.search-kbd {
  flex-shrink: 0;
  font-family: inherit;
  font-size: 0.7rem;
  padding: 2px 6px;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  background: var(--bg-block);
  color: var(--text-muted);
  line-height: 1.4;
}

.search-results {
  max-height: 420px;
  overflow-y: auto;
  padding: 0.5rem 0;
}
.search-hint {
  padding: 1.5rem 1rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.search-result-item {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  padding: 0.6rem 1rem;
  text-decoration: none;
  color: var(--text-color);
  transition: background 0.15s;
}
.search-result-item:hover,
.search-result-item.is-active {
  background: var(--bg-menu-hover);
}
.search-result-item .result-date {
  flex-shrink: 0;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  min-width: 5.5em;
}
.search-result-item .result-title {
  font-size: 0.92rem;
  line-height: 1.4;
  color: var(--text-color);
}
.search-result-item:hover .result-title,
.search-result-item.is-active .result-title {
  color: var(--link-hover);
}
.search-meta {
  padding: 0.5rem 1rem 0.75rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-light);
}

@media (max-width: 480px) {
  .search-dropdown {
    padding: 58px 0.5rem 0;
  }
  .search-result-item {
    flex-direction: column;
    gap: 0.2rem;
  }
  .search-result-item .result-date {
    min-width: unset;
  }
}

/* ===========================
   Main Content
   =========================== */
.main-content,
.wrap {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}
.main-content ul, .main-content ol,
.wrap ul, .wrap ol {
  padding-left: 1.5rem;
  margin: 0.8em 0;
}
.main-content li,
.wrap li {
  list-style: none;
}
.main-content li::before {
  content: '• ';
  color: var(--accent);
}
.main-content li li::before { content: '◦ '; }
.main-content li li li::before { content: '▸ '; }
.wrap li::before {
  content: '• ';
  color: var(--accent);
}
.wrap li li::before { content: '◦ '; }
.wrap li li li::before { content: '▸ '; }
.main-content p,
.wrap p {
  word-break: break-word;
}
.post-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.post-list li {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border-light);
}
.post-list li:last-child { border-bottom: none; }
.post-list .date {
  color: var(--text-muted);
  font-size: 0.85rem;
  white-space: nowrap;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  min-width: 80px;
}
.post-list a {
  color: var(--text-color);
  font-size: 1rem;
}
.post-list a:hover { color: var(--link-hover); }


/* ===========================
   Taxonomy Index
   =========================== */
.taxonomy-index {
  max-width: 1040px;
}

.taxonomy-hero {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  margin: 0 0 1.35rem;
  padding: 1.25rem 1.4rem;
  border: 1px solid var(--border-light);
  border-radius: 14px;
  background: color-mix(in srgb, var(--bg-card) 84%, var(--bg-block));
  box-shadow: var(--shadow-soft);
}

.taxonomy-heading {
  display: inline-block;
  margin: 0;
  padding-bottom: 0.35rem;
  color: var(--h1-color);
  border-bottom: 2px solid var(--accent);
}

.taxonomy-stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.5rem;
}

.taxonomy-stats span {
  display: inline-flex;
  align-items: baseline;
  gap: 0.32rem;
  padding: 0.38rem 0.68rem;
  border: 1px solid var(--border-light);
  border-radius: 999px;
  background: var(--bg-body);
  color: var(--text-muted);
  font-size: 0.85rem;
}

.taxonomy-stats strong {
  color: var(--h1-color);
  font-size: 1rem;
}

.taxonomy-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 0.9rem;
}

.taxonomy-card {
  --taxonomy-tone: var(--accent);
  position: relative;
  overflow: hidden;
  border: 1px solid var(--border-light);
  border-radius: 12px;
  background: var(--bg-card);
  box-shadow: var(--shadow-soft);
  transition: transform 0.18s ease, border-color 0.18s ease, background-color 0.18s ease, box-shadow 0.18s ease;
}

.taxonomy-card::before {
  content: '';
  position: absolute;
  inset: 0 0 auto;
  height: 3px;
  background: linear-gradient(90deg, var(--taxonomy-tone), color-mix(in srgb, var(--taxonomy-tone) 18%, transparent));
  opacity: 0.72;
}

.taxonomy-card:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--taxonomy-tone) 32%, var(--border-light));
  background: color-mix(in srgb, var(--taxonomy-tone) 5%, var(--bg-card));
  box-shadow: 0 8px 22px rgba(44, 36, 24, 0.08);
}

html.dark .taxonomy-card:hover {
  box-shadow: 0 8px 22px rgba(0, 0, 0, 0.24);
}

.taxonomy-card-head {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.75rem;
  align-items: center;
  padding: 1rem 1rem 0.8rem;
  color: var(--text-color);
  text-decoration: none;
}

.taxonomy-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.15rem;
  height: 2.15rem;
  border: 1px solid color-mix(in srgb, var(--taxonomy-tone) 24%, var(--border-light));
  border-radius: 10px;
  background: color-mix(in srgb, var(--taxonomy-tone) 9%, var(--bg-card));
  color: var(--taxonomy-tone);
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  font-size: 0.92rem;
  font-weight: 700;
}

.taxonomy-title-wrap {
  min-width: 0;
}

.taxonomy-title {
  display: block;
  min-width: 0;
  color: var(--text-heading);
  font-size: 1.08rem;
  font-weight: 700;
  line-height: 1.25;
}

.taxonomy-desc {
  display: block;
  margin-top: 0.18rem;
  color: var(--text-muted);
  font-size: 0.82rem;
  line-height: 1.45;
}

.taxonomy-count {
  display: inline-flex;
  align-items: baseline;
  gap: 0.18rem;
  padding: 0.28rem 0.5rem;
  border-radius: 999px;
  background: var(--bg-block);
  color: var(--text-muted);
}

.taxonomy-count strong {
  color: var(--h1-color);
  font-size: 1rem;
  line-height: 1;
}

.taxonomy-count em {
  font-size: 0.72rem;
  font-style: normal;
}

.taxonomy-subgrid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.42rem;
  padding: 0 1rem 1rem;
}

.taxonomy-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.38rem;
  max-width: 100%;
  padding: 0.34rem 0.56rem;
  border: 1px solid var(--border-light);
  border-radius: 999px;
  background: color-mix(in srgb, var(--bg-card) 70%, var(--bg-block));
  color: var(--text-color);
  font-size: 0.86rem;
  line-height: 1.2;
  text-decoration: none;
  transition: background 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}

.taxonomy-chip:hover {
  border-color: color-mix(in srgb, var(--taxonomy-tone) 35%, var(--border-light));
  background: color-mix(in srgb, var(--taxonomy-tone) 8%, var(--bg-card));
  color: var(--link-hover);
}

.taxonomy-chip span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.taxonomy-chip strong {
  color: var(--text-muted);
  font-size: 0.76rem;
}

.taxonomy-empty {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.taxonomy-tone-blue { --taxonomy-tone: var(--accent-blue); }
.taxonomy-tone-green { --taxonomy-tone: #16a34a; }
.taxonomy-tone-purple { --taxonomy-tone: #8b5cf6; }
.taxonomy-tone-amber { --taxonomy-tone: #d97706; }
.taxonomy-tone-cyan { --taxonomy-tone: #0891b2; }
.taxonomy-tone-rose { --taxonomy-tone: #e11d48; }
.taxonomy-tone-teal { --taxonomy-tone: #0d9488; }
.taxonomy-tone-neutral { --taxonomy-tone: var(--accent); }

/* Legacy category table, kept for older generated/custom pages. */
.cat-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
}
.cat-table tr {
  border-bottom: 1px solid var(--border-light);
}
.cat-table tr:last-child {
  border-bottom: none;
}
.cat-table td {
  padding: 18px 20px;
  border-bottom: 1px solid var(--border-light);
}
.cat-table tr:last-child td {
  border-bottom: none;
}
.cat-table .cat-name {
  vertical-align: middle;
  white-space: nowrap;
  text-align: center;
  padding-right: 32px;
}
.cat-table .cat-name a {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-color);
  text-decoration: none;
}
.cat-table .cat-name a:hover {
  color: var(--link-color);
}
.cat-table .cat-count {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-left: 4px;
}
.cat-table .cat-subs {
  vertical-align: middle;
  line-height: 1.8;
}
.cat-table .cat-subs a {
  display: inline-block;
  margin: 2px 6px 2px 0;
  font-size: 0.95rem;
  color: var(--text-color);
  text-decoration: none;
  padding: 2px 8px;
  border-radius: 4px;
  transition: background 0.15s, color 0.15s;
}
.cat-table .cat-subs a:hover {
  background: var(--bg-menu-hover);
  color: var(--link-color);
}
.cat-table .cat-subs .sub-count {
  color: var(--text-muted);
  font-size: 0.8rem;
}
.cat-table .cat-subs .sep {
  color: var(--border-color);
  margin: 0 4px;
}
.cat-table .cat-subs .empty-mark {
  color: var(--text-muted);
  font-size: 0.9rem;
}

@media (max-width: 640px) {
  .taxonomy-hero {
    align-items: flex-start;
    flex-direction: column;
    gap: 0.85rem;
    padding: 1rem;
    border-radius: 12px;
  }

  .taxonomy-stats {
    justify-content: flex-start;
  }

  .taxonomy-grid {
    grid-template-columns: 1fr;
  }

  .taxonomy-card-head {
    grid-template-columns: auto 1fr;
  }

  .taxonomy-count {
    grid-column: 1 / -1;
    flex-direction: row;
    justify-content: flex-start;
    width: fit-content;
  }
}

/* View subcategory link on category pages */
.subcat-heading {
  display: inline-block;
  color: var(--h1-color);
  text-decoration: none;
  border-bottom: 2px solid var(--accent);
  padding-bottom: 8px;
  margin-bottom: 16px;
  transition: color 0.15s, border-color 0.15s;
}
.subcat-heading:hover {
  color: var(--link-color);
  border-color: var(--link-color);
}

/* ===========================
   Hero
   =========================== */
.hero {
  position: relative;
  height: 55vh;
  min-height: 360px;
  background: var(--hero-grad);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(255,255,255,.04) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 30%, rgba(212,167,106,.06) 0%, transparent 50%);
}
.hero-inner { text-align: center; z-index: 1; padding: 20px; }
.hero-inner h1 {
  font-size: clamp(2.2rem, 6vw, 4rem);
  font-weight: 800;
  color: var(--hero-text);
  letter-spacing: -0.02em;
  text-shadow: 0 2px 20px rgba(0,0,0,.4);
}
.hero-inner .sub {
  font-size: clamp(0.9rem, 2vw, 1.2rem);
  color: var(--hero-sub);
  font-weight: 300;
  letter-spacing: 0.3em;
  text-shadow: 0 1px 8px rgba(0,0,0,0.5);
}
.hero-inner .tagline {
  margin-top: 16px;
  font-size: 0.95rem;
  color: var(--hero-sub);
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
  text-shadow: 0 1px 8px rgba(0,0,0,0.5);
}

/* ===========================
   Stats
   =========================== */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0;
  background: var(--accent);
  margin: 0 auto;
}
.stats > div {
  background: var(--bg-block);
  padding: 20px 12px;
  text-align: center;
  transition: background 0.3s;
}
.stats > div:hover { background: var(--bg-card-hover); }
.stats .num { font-size: 2.2rem; font-weight: 800; color: var(--accent); }
.stats .num.g { color: var(--accent-gold); }
.stats .num.b { color: var(--accent-blue); }
.stats .label { font-size: 0.8rem; color: var(--text-muted); margin-top: 4px; display: block; }
.stats .label.g { color: var(--accent-gold); }
.stats .label.b { color: var(--accent-blue); }

/* ===========================
   Section
   =========================== */
.section { margin-bottom: 60px; }
.section-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--h2-color);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent);
}

/* ===========================
   Card Grid
   =========================== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin: 30px 0;
}
.card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 24px;
  border: 1px solid var(--border-light);
  transition: background 0.3s, transform 0.2s, box-shadow 0.2s;
}
.card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-soft);
}
.card h3 { margin: 0 0 12px 0; color: var(--text-heading); }
.card p { color: var(--text-muted); font-size: 0.95rem; line-height: 1.6; margin: 0; }

/* ===========================
   Icon Grid
   =========================== */
.icon-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin: 30px 0;
}
.icon-item {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 24px;
  text-align: center;
  border: 1px solid var(--border-light);
  transition: background 0.3s;
}
.icon-item:hover { background: var(--bg-card-hover); }
.icon-item .icon { font-size: 2.5rem; margin-bottom: 10px; }
.icon-item .label { font-size: 0.9rem; color: var(--text-muted); }
.icon-item .sub-label { font-size: 0.8rem; color: var(--text-muted); margin-top: 4px; opacity: 0.7; }


/* ===========================
   Ch Chapter (编年叙事)
   =========================== */
.ch { margin-bottom: 70px; }
.ch.card { background: var(--bg-block); border: 1px solid var(--border-color); border-radius: 12px; padding: 2rem; margin-top: 1.5rem; }
.ch-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent-blue);
  margin-bottom: 4px;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}
.ch-title {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 14px;
  border-bottom: 2px solid var(--accent);
  display: block;
  width: fit-content;
  padding-bottom: 6px;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}
.ch-subtitle {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--h3-color);
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}
.ch-section {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--h4-color);
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}

/* Definition list — Term :: Definition */
.ch li dl { margin: 0; display: inline; }
.ch dt {
  font-weight: 600;
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  padding: 1px 6px;
  border-radius: 4px;
  display: inline;
}
.ch dt::after { content: ""; }
.ch dd { display: inline; margin: 0; color: var(--text-body); }
.ch dd::before { content: " "; }

/* Term list — dl.term-list with li/p.term */
.term-list { margin: 0.5em 0; }
.term-list li.term, p.term { margin: 0.3em 0; list-style: none; }
.term-list dt {
  font-weight: 600;
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  padding: 1px 6px;
  border-radius: 4px;
  display: inline;
}
.term-list dd {
  margin: 0;
  color: var(--text-body);
  display: inline;
  margin-left: 0.4em;
}
.ch-date {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}
.ch p {
  margin-bottom: 14px;
  color: var(--text-color);
  font-size: 0.95rem;
  line-height: 1.9;
}
.ch h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-heading);
  margin: 28px 0 10px;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}


/* ===========================
   Photo
   =========================== */
.photo {
  margin: 28px 0;
  border-radius: 10px;
  overflow: hidden;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  transition: box-shadow 0.3s;
}
.photo:hover { box-shadow: var(--shadow-soft); }
.photo img,
.photo video {
  width: 100%;
  display: block;
  transition: transform 0.5s ease;
}
.photo video {
  height: auto;
}
.photo:hover img { transform: scale(1.01); }
.photo .cap {
  padding: 12px 18px;
  font-size: 0.82rem;
  color: var(--text-muted);
  font-style: italic;
  border-top: 1px solid var(--border-light);
}

/* ===========================
   Quote
   =========================== */
.quote {
  border-left: 4px solid var(--accent);
  padding: 18px 22px;
  margin: 22px 0;
  background: var(--bg-block);
  border-radius: 0 8px 8px 0;
}
.quote p { font-style: italic; color: var(--text-color); margin: 0; }
.quote .who { font-size: 0.85rem; color: var(--text-muted); margin-top: 8px; font-style: normal; }


/* ===========================
   Callout / Info Box
   =========================== */
.callout {
  padding: 22px; margin: 24px 0; border-radius: 10px;
  background: linear-gradient(135deg, rgba(212,160,23,.08), rgba(212,160,23,.03));
  border: 1px solid rgba(212,160,23,.18);
}
.callout h3 { color: var(--accent-gold); margin-bottom: 8px; }
.callout p { color: var(--text-muted); font-size: 0.9rem; }

.info-box {
  padding: 22px; margin: 24px 0; border-radius: 10px;
  background: linear-gradient(135deg, rgba(50,135,208,.08), rgba(50,135,208,.03));
  border: 1px solid rgba(50,135,208,.18);
}
.info-box h3 { color: var(--accent-blue); margin-bottom: 8px; }
.info-box p { color: var(--text-muted); font-size: 0.9rem; }

/* ===========================
   Table
   =========================== */
/* Fallback for tables not yet wrapped by JS */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  font-size: 0.88rem;
}
th {
  background: var(--tbl-head-bg); color: var(--tbl-head-fg);
  padding: 10px 14px; text-align: left; font-weight: 600;
}
td {
  padding: 8px 14px;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-muted);
  word-break: break-word;
  overflow-wrap: break-word;
  white-space: normal;
}
tr:hover td { background: var(--bg-card-hover); }

/* Scrollable table wrapper */
.table-wrap {
  margin: 18px 0 0;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  overflow: hidden;
}
.table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.table-wrap table {
  width: 100%;
  margin: 0;
}
.table-wrap.wide table {
  width: max-content;
  min-width: 100%;
}
.table-wrap.wide th,
.table-wrap.wide td {
  white-space: nowrap;
}

.table-wrap.wrap-table table {
  width: 100%;
  table-layout: fixed;
}

.table-wrap.wrap-table th,
.table-wrap.wrap-table td {
  white-space: normal;
  overflow-wrap: anywhere;
  word-break: normal;
  vertical-align: top;
}

.table-wrap.param-table table {
  width: max-content;
  min-width: 100%;
}

.table-wrap.param-table th:first-child,
.table-wrap.param-table td:first-child {
  width: 1%;
  white-space: nowrap;
}

.table-wrap.param-table th:not(:first-child),
.table-wrap.param-table td:not(:first-child) {
  min-width: 18rem;
  white-space: normal;
}

/* MathJax block formula wrapper — allow horizontal scroll for wide formulas */
.math-block {
  width: 100%;
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: 18px 0;
  padding: 4px 0;
  box-sizing: border-box;
  text-align: center;
}
.math-block mjx-block {
  display: inline-block !important;
  max-width: 100% !important;
  text-align: left;
}
.math-block mjx-container[display="block"] {
  display: inline-block !important;
}

/* MathJax inline — stays in text flow */
.math-inline {
  display: inline;
  white-space: normal;
  vertical-align: baseline;
}
.math-inline mjx-container,
.math-inline mjx-container svg {
  display: inline-block !important;
  vertical-align: -0.15em;
}

/* Citation references — <cite>$key$</cite> */
cite {
  font-style: normal;
  color: var(--text-muted);
  background: var(--bg-hover);
  border-radius: 4px;
  padding: 0 4px;
  font-size: 0.9em;
}

cite.cite-enhanced {
  cursor: pointer;
  border-bottom: 1px dashed var(--accent);
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

cite.cite-enhanced:hover,
cite.cite-enhanced:focus {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 12%, var(--bg-hover));
  outline: none;
}

.cite-popover {
  position: absolute;
  z-index: 1200;
  width: min(420px, calc(100vw - 32px));
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  background: color-mix(in srgb, var(--bg-card) 94%, black 6%);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.18);
  color: var(--text-primary);
  backdrop-filter: blur(10px);
}

.cite-popover-key {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.45rem;
}

.cite-popover-text {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-primary);
}

.cite-popover-link,
.cite-popover-muted {
  display: inline-block;
  margin-top: 0.7rem;
  font-size: 0.82rem;
}

.cite-popover-link {
  color: var(--accent);
  text-decoration: none;
}

.cite-popover-link:hover {
  text-decoration: underline;
}

.cite-popover-muted {
  color: var(--text-muted);
}

.cite-reference {
  scroll-margin-top: 96px;
  transition: background-color 0.35s ease, box-shadow 0.35s ease;
}

.cite-reference-highlight {
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 28%, transparent);
  border-radius: 8px;
}

/* ===========================
   Tags / Badges
   =========================== */
.tags { display: flex; flex-wrap: wrap; gap: 6px; margin: 12px 0; }
.tag,
span.tag {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 0.75rem;
  border: 1px solid var(--border-color);
  background: var(--bg-block);
  color: var(--text-muted);
}
.meta-tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.5rem; }
.meta-tag {
  display: inline-block; padding: 2px 8px;
  background: var(--bg-block); border: 1px solid var(--border-color);
  border-radius: 4px; font-size: 0.8rem; color: var(--text-muted);
  text-decoration: none;
}
.meta-tag:hover { background: var(--bg-menu-hover); color: var(--link-color); }

.badge {
  display: inline-block; padding: 2px 10px; border-radius: 12px;
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.05em;
}
.badge.europe { background: rgba(233,69,96,.15); color: var(--accent); }
.badge.china { background: rgba(240,192,64,.15); color: var(--accent-gold); }
.badge.japan { background: rgba(74,158,255,.15); color: var(--accent-blue); }
.badge.britain { background: rgba(100,200,100,.15); color: #4caf50; }

/* ===========================
   Article Meta
   =========================== */
.article-meta {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-light);
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}

.meta-primary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.6rem;
}

.meta-item {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.meta-item svg {
  color: var(--text-muted);
  opacity: 0.7;
  flex-shrink: 0;
}

.meta-sep {
  color: var(--border-color);
  font-size: 0.85rem;
  user-select: none;
}

.article-meta .date,
.article-meta .reading-time {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.meta-tags-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
}

.meta-tags-row svg {
  color: var(--text-muted);
  opacity: 0.6;
  flex-shrink: 0;
}

/* Meta tag pill */
.meta-tag {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 14px;
  background: var(--bg-menu);
  color: var(--text-muted);
  font-size: 0.82rem;
  text-decoration: none;
  transition: background 0.2s, color 0.2s, transform 0.15s;
  border: 1px solid var(--border-light);
}

.meta-tag:hover {
  background: var(--bg-menu-hover);
  color: var(--link-color);
  text-decoration: none;
  transform: translateY(-1px);
}

/* Category tag: prominent, use accent color */
.meta-item .meta-tag {
  font-weight: 600;
  color: var(--accent);
  background: rgba(139, 94, 52, 0.08);
  border-color: rgba(139, 94, 52, 0.2);
}

.meta-item .meta-tag:hover {
  background: rgba(139, 94, 52, 0.15);
  color: var(--link-hover);
}

/* Tag row: smaller, neutral */
.meta-tags-row .meta-tag {
  font-size: 0.78rem;
  padding: 2px 10px;
  color: var(--text-muted);
  background: var(--bg-block);
  border-color: var(--border-light);
}

.meta-tags-row .meta-tag:hover {
  background: var(--bg-menu);
  color: var(--link-color);
}

/* ===========================
   Article Footer
   =========================== */
.article-footer {
  margin-top: 2rem;
  padding-top: 1rem;
}
.article-footer .footer-row {
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}
.article-footer .footer-label {
  font-weight: 600;
  margin-right: 0.5rem;
  color: var(--text-heading);
}
.article-footer a {
  color: var(--link-color);
  text-decoration: none;
}
.article-footer a:hover {
  color: var(--link-hover);
  text-decoration: underline;
}
.article-footer .sep {
  color: var(--border-color);
}

/* ===========================
   Sources (参考来源)
   =========================== */
.sources {
  margin: 2em 0;
  padding: 1em 1.25em;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background: var(--bg-block);
}
.sources h3,
.sources .section-title {
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.75em;
}
.sources .section-title:not(:first-child) {
  margin-top: 1.5em;
  padding-top: 1.25em;
  border-top: 1px solid var(--border-color);
}
.sources ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.4em;
}
.sources li {
  font-size: 0.9rem;
  line-height: 1.5;
  word-break: break-all;
}
.sources a {
  color: var(--link-color);
  text-decoration: none;
}
.sources a:hover {
  color: var(--link-hover);
  text-decoration: underline;
}


/* ===========================
   Fade-in Animation
   =========================== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===========================
   Footer
   =========================== */
.site-footer {
  border-top: 1px solid var(--border-color);
  padding: 1.5rem 1.5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 3rem;
}
.site-footer a { color: var(--link-color); text-decoration: none; }
.site-footer a:hover { color: var(--link-hover); }

/* ===========================
   Back-to-top
   =========================== */
/* ===========================
   Float Buttons (bottom-right column)
   =========================== */
.float-btns {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  z-index: 800;
}
.float-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: var(--bg-block);
  color: var(--text-color);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-soft);
  transition: background 0.2s, transform 0.15s;
}
.float-btn:hover { background: var(--bg-menu-hover); transform: translateY(-2px); }
.float-music { font-size: 18px; }
.float-music.playing { color: var(--accent-blue); }

/* Back-to-top: show on scroll */
#back-to-top {
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
}
#back-to-top.is-visible { opacity: 1; visibility: visible; }
#back-to-top:hover { background: var(--bg-menu-hover); transform: translateY(-2px); }
#back-to-top svg { width: 22px; height: 22px; }

/* TOC drawer trigger hidden in nav */
.nav-toc-btn, .nav-music-btn { display: none; }

@media (max-width: 768px) {
  .float-btns { bottom: 1rem; right: 1rem; }
  .float-btn { width: 40px; height: 40px; }
}

/* ===========================
   Responsive
   =========================== */
@media (max-width: 768px) {
  .main-content, .wrap { padding: 1.25rem 1rem; }
  .hero { height: 45vh; min-height: 300px; }
  .card-grid { grid-template-columns: 1fr; }
  .icon-grid { grid-template-columns: 1fr 1fr; }
  .post-list li { flex-direction: column; gap: 0.15rem; }
  .post-list li::before { content: none; display: none; }
  .post-list .date { font-size: 0.8rem; }
  .back-to-top { bottom: 1rem; right: 1rem; width: 40px; height: 40px; }
  .vs { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); }
}


/* ===========================
   TOC Sidebar (参考 Hugo 博客)
   =========================== */
:root {
  --toc-nav-offset: 56px;
}

.toc-sidebar {
  position: fixed;
  left: 0;
  top: var(--toc-nav-offset);
  height: calc(100vh - var(--toc-nav-offset));
  background: color-mix(in srgb, var(--bg-block) 94%, white 6%);
  border-top: 1px solid var(--border-light);
  border-right: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-light);
  border-top-right-radius: 12px;
  border-bottom-right-radius: 8px;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

html.dark .toc-sidebar {
  background: color-mix(in srgb, var(--bg-block) 96%, black 4%);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.28);
}

/* Toggle button */
.toc-toggle-btn {
  position: fixed;
  top: calc(50% + var(--toc-nav-offset) / 2);
  transform: translateY(-50%);
  width: 24px;
  height: 80px;
  background: color-mix(in srgb, var(--bg-block) 94%, white 6%);
  border: 1px solid var(--border-color);
  border-left: none;
  border-radius: 0 10px 10px 0;
  box-shadow: 0 6px 20px rgba(15, 23, 42, 0.08);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-color);
  transition: left 0.3s ease, width 0.2s ease, background 0.2s, box-shadow 0.2s;
  z-index: 999;
}

html.dark .toc-toggle-btn {
  background: color-mix(in srgb, var(--bg-block) 96%, black 4%);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.28);
}
.toc-toggle-btn:hover {
  background: var(--bg-menu-hover);
  width: 28px;
}

/* TOC toggle button positioned by JS */
.toc-toggle-btn svg {
  transition: transform 0.3s ease;
}
.toc-sidebar.toc-collapsed ~ .toc-toggle-btn svg {
  transform: rotate(180deg);
}
.toc-sidebar.toc-collapsed { min-width: 0; max-width: 0; border: none; }

/* TOC header */
.toc-section {
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.toc-main-section { flex: 1 1 45%; }
.categories-section {
  flex: 1 1 55%;
  background: color-mix(in srgb, var(--bg-block) 97%, var(--bg-nav) 3%);
}
html.dark .categories-section {
  background: color-mix(in srgb, var(--bg-block) 98%, black 2%);
}
.toc-split-handle {
  position: relative;
  flex: 0 0 8px;
  height: 8px;
  cursor: row-resize;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-block);
  transition: background 0.15s, border-color 0.15s;
}
.toc-split-handle::after {
  content: '';
  position: absolute;
  left: 50%;
  top: 50%;
  width: 34px;
  height: 2px;
  transform: translate(-50%, -50%);
  border-radius: 999px;
  background: var(--border-color);
}
.toc-split-handle:hover,
.toc-split-handle.is-dragging {
  background: var(--bg-menu-hover);
  border-color: var(--accent-blue);
}
.toc-split-handle:hover::after,
.toc-split-handle.is-dragging::after {
  background: var(--accent-blue);
}
.toc-header {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 56px;
  padding: 0 14px;
  border-bottom: 1px solid var(--border-light);
  background: linear-gradient(to bottom, color-mix(in srgb, var(--bg-nav) 72%, var(--bg-block) 28%), color-mix(in srgb, var(--bg-block) 96%, transparent 4%));
  font-weight: 600;
  font-size: 14px;
  flex-shrink: 0;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}
html.dark .toc-header {
  background: linear-gradient(to bottom, color-mix(in srgb, var(--bg-nav) 78%, var(--bg-block) 22%), color-mix(in srgb, var(--bg-block) 98%, transparent 2%));
}
.toc-title { color: var(--text-color); }

/* TOC content */
.toc-content {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 16px 8px 16px 0;
}
.toc-content::-webkit-scrollbar { width: 6px; }
.toc-content::-webkit-scrollbar-track { background: transparent; }
.toc-content::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 3px; }

/* Resize handle */
.toc-resize-handle {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  cursor: col-resize;
  background: transparent;
  transition: background 0.15s;
  z-index: 10;
}
.toc-resize-handle:hover {
  background: var(--accent-blue);
}

/* TOC list */
.toc-tree { margin: 0; }
.toc-tree ul {
  padding-left: 0;
  list-style: none;
  margin: 0;
}

/* Each item is a flex row: [arrow/dot] [link] */
.toc-tree li {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  margin: 0;
  width: 100%;
}

/* Toggle arrow — always visible */
.toc-toggle {
  flex-shrink: 0;
  width: 20px;
  height: 22px;
  border: none;
  background: none;
  cursor: pointer;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  opacity: 0.55;
  transition: opacity 0.15s, color 0.15s, background 0.15s;
  border-radius: 3px;
}
.toc-toggle:hover {
  opacity: 1;
  color: var(--accent-blue);
  background: var(--bg-menu-hover);
}
.toc-toggle svg {
  transition: transform 0.2s ease;
}

/* Leaf dot — small bullet for items without children */
.toc-dot {
  flex-shrink: 0;
  width: 20px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.toc-dot::after {
  content: '';
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--border-color);
}

/* Link text */
.toc-tree a {
  flex: 1;
  min-width: 0;
  padding: 3px 6px;
  color: var(--text-muted);
  text-decoration: none;
  border-radius: 0 4px 4px 0;
  border-left: 2px solid transparent;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  font-size: 13px;
  line-height: 1.6;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Bright mode: strengthen hierarchy between level-2 and level-3 headings */
#toc-nav a[data-level="2"] {
  font-size: 13.5px;
  font-weight: 620;
  color: #1f2937;
  letter-spacing: 0.01em;
}
#toc-nav a[data-level="3"] {
  font-size: 12.5px;
  font-weight: 500;
  color: #667085;
  padding-left: 10px;
}
#toc-nav a[data-level="4"],
#toc-nav a[data-level="5"],
#toc-nav a[data-level="6"] {
  font-size: 12px;
  color: #8a94a6;
  padding-left: 14px;
}

html.dark #toc-nav a[data-level="2"] {
  color: var(--text-color);
}
html.dark #toc-nav a[data-level="3"] {
  color: var(--text-muted);
  padding-left: 8px;
}
html.dark #toc-nav a[data-level="4"],
html.dark #toc-nav a[data-level="5"],
html.dark #toc-nav a[data-level="6"] {
  color: var(--text-muted);
  opacity: 0.82;
  padding-left: 12px;
}
.toc-tree a:hover {
  color: var(--text-color);
  background: var(--bg-menu-hover);
}
.category-browser-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  padding: 0 2px 6px;
  border-bottom: 1px solid var(--border-light);
}
.category-back {
  flex-shrink: 0;
  border: none;
  background: var(--bg-block);
  color: var(--text-muted);
  border-radius: 4px;
  padding: 3px 7px;
  font-size: 12px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, opacity 0.15s;
}
.category-back:not(:disabled):hover {
  background: var(--bg-menu-hover);
  color: var(--accent-blue);
}
.category-back:disabled {
  cursor: default;
  opacity: 0.38;
}
.category-breadcrumb {
  min-width: 0;
  color: var(--text-muted);
  font-size: 12px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.category-breadcrumb-link {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}
.category-breadcrumb-link:hover {
  color: var(--accent-blue);
  text-decoration: underline;
}
.category-breadcrumb-sep {
  color: var(--text-muted);
  opacity: 0.6;
}
.category-folder-label {
  flex: 1;
  min-width: 0;
  border: none;
  background: none;
  padding: 3px 6px;
  color: var(--text-muted);
  text-align: left;
  border-radius: 0 4px 4px 0;
  border-left: 2px solid transparent;
  cursor: pointer;
  font-size: 13px;
  line-height: 1.6;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.category-folder-label:hover {
  color: var(--text-color);
  background: var(--bg-menu-hover);
  border-left-color: var(--border-color);
}
.category-file-link.active {
  color: var(--accent-blue);
  font-weight: 600;
  background: var(--bg-menu-hover);
  border-left-color: var(--accent-blue);
}
#toc-nav a.active {
  color: var(--accent-blue);
  font-weight: 600;
  background: var(--bg-menu-hover);
  border-left-color: var(--accent-blue);
}

/* TOC inline MathJax — keep formulas embedded in heading text */
#toc-nav a mjx-container,
#toc-nav a mjx-container[jax="SVG"],
#category-nav a mjx-container,
#category-nav a mjx-container[jax="SVG"],
.mobile-toc-nav li a mjx-container,
.mobile-toc-nav li a mjx-container[jax="SVG"] {
  display: inline-block !important;
  position: static !important;
  vertical-align: -0.15em;
  max-width: 100%;
}
#toc-nav a mjx-container svg,
#category-nav a mjx-container svg,
.mobile-toc-nav li a mjx-container svg {
  display: inline-block !important;
}
#toc-nav a mjx-assistive-mml,
#category-nav a mjx-assistive-mml,
.mobile-toc-nav li a mjx-assistive-mml {
  display: none !important;
}

/* Top-level items (direct children of .toc-tree > ul) */
.toc-tree > ul > li > a,
.category-browser-list > ul > li > .category-folder-label {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-color);
}

/* Tree guide lines — border-left inside children, clipped by sidebar */
.toc-tree {
  overflow-x: hidden;
}
.toc-tree ul {
  overflow-x: visible;
}
.toc-tree li {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  margin: 0;
  width: 100%;
  overflow: visible;
  position: relative; /* anchor for absolutely-positioned guide lines */
}
/* Children are flex items whose border-left is inside overflow:hidden clipping */
.toc-tree .toc-children {
  flex-basis: 100%;
  overflow: hidden;
  padding-left: 0;
  margin-left: 0;
  /* Guide line: border-left on the children element */
  border-left: 1.5px solid var(--border-light);
}
.toc-children a { font-size: 1rem; }
.toc-children .toc-children a { font-size: 0.95rem; }
.toc-children .toc-children .toc-children a { font-size: 0.9rem; }
.category-nav .toc-children a { font-size: 0.92rem; }
.category-nav .toc-children .toc-children a { font-size: 0.84rem; }

/* Collapsed state */
.toc-parent.toc-collapsed > .toc-toggle svg {
  transform: rotate(-90deg);
}
.toc-parent.toc-collapsed > .toc-children {
  display: none;
}

/* Main wrapper shift */
.main-wrapper {
  transition: padding-left 0.3s ease;
}
/* Main content shift — handled by JS (main-wrapper padding-left synced with sidebar width) */

/* Responsive */
@media (max-width: 1024px) {
  :root {
    --toc-nav-offset: 56px;
  }
  .toc-sidebar,
  .toc-toggle-btn {
    display: none !important;
  }
  .main-wrapper {
    padding-left: 0 !important;
  }
  /* Mobile TOC button in nav */
  .nav-toc-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-block);
    cursor: pointer;
    color: var(--text-color);
  }
  .nav-toc-btn:hover { background: var(--bg-menu-hover); }
}

/* Hide mobile TOC button on desktop */
@media (min-width: 1025px) {
  .nav-toc-btn { display: none; }
  .mobile-toc-overlay, .mobile-toc-drawer { display: none !important; }
}

/* Mobile TOC drawer */
.mobile-toc-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 2000;
  opacity: 0;
  transition: opacity 0.3s;
}
.mobile-toc-overlay.is-open {
  display: block;
  opacity: 1;
}
.mobile-toc-drawer {
  position: fixed;
  right: 0;
  top: var(--toc-nav-offset);
  height: calc(100vh - var(--toc-nav-offset));
  width: min(300px, 85vw);
  background: var(--bg-block);
  border-left: 1px solid var(--border-color);
  z-index: 2001;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}
.mobile-toc-drawer.is-open {
  transform: translateX(0);
}
.mobile-toc-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  font-weight: 700;
  font-size: 1rem;
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}
.mobile-toc-close {
  width: 32px; height: 32px;
  border: none;
  background: none;
  cursor: pointer;
  font-size: 1.1rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
}
.mobile-toc-close:hover { background: var(--bg-menu-hover); }
.mobile-toc-nav {
  padding: 12px 0;
  overflow-y: auto;
  flex: 1;
}
.mobile-toc-nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.mobile-toc-nav li a {
  display: block;
  padding: 10px 20px;
  color: var(--text-color);
  text-decoration: none;
  font-size: 0.88rem;
  border-left: 3px solid transparent;
  transition: background 0.2s, border-color 0.2s;
}
.mobile-toc-nav li a:hover {
  background: var(--bg-menu-hover);
  border-left-color: var(--accent);
}
.mobile-toc-nav li.toc-h3 a { padding-left: 36px; font-size: 0.84rem; }
.mobile-toc-nav li.toc-h4 a { padding-left: 48px; font-size: 0.8rem; color: var(--text-muted); }


/* ===========================
   Anchor icons on headings
   =========================== */
.anchor {
  display: inline-block;
  margin-right: 0.4rem;
  opacity: 0.3;
  transition: opacity 0.2s;
  vertical-align: middle;
}
.anchor-icon { width: 16px; height: 16px; }
h1:hover .anchor, h2:hover .anchor, h3:hover .anchor, h4:hover .anchor { opacity: 1; }

/* ===========================
   Bilibili embed
   =========================== */
.bilibili-embed {
  margin: 1.5em auto;
  display: flex;
  justify-content: center;
}
.bilibili-embed iframe {
  width: 640px;
  height: 360px;
  border-radius: 12px;
  border: none;
  max-width: 100%;
  aspect-ratio: 16/9;
}
@media (max-width: 768px) {
  .bilibili-embed iframe { width: 100%; }
}

/* ===========================
   Image block (wiki image shortcode)
   =========================== */
.image {
  margin: 1.5em 0;
  text-align: center;
}
.image img {
  display: inline-block;
  max-width: 100%;
  border-radius: 8px;
  margin: 0 auto;
}
.image .caption {
  margin-top: 0.5em;
  font-size: 0.82rem;
  color: var(--text-muted);
  font-style: italic;
  text-align: center;
}

/* ===========================
   Admonition blocks
   =========================== */
.admonition {
  margin: 1.5em 0;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid;
}
.admonition-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6em 1em;
  font-weight: 700;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  font-size: 0.95rem;
}
.admonition-title .icon { width: 18px; height: 18px; }
.admonition-content { padding: 1em; font-size: 0.95rem; }
.admonition-content p:last-child { margin-bottom: 0; }

.admonition.note   { border-color: var(--accent-blue); }
.admonition.note   .admonition-title { background: rgba(50,135,208,.1); color: var(--accent-blue); }
.admonition.tip    { border-color: var(--accent-gold); }
.admonition.tip    .admonition-title { background: rgba(212,160,23,.1); color: var(--accent-gold); }
.admonition.warning { border-color: #d97706; }
.admonition.warning .admonition-title { background: rgba(217,119,6,.1); color: #d97706; }
.admonition.danger  { border-color: var(--accent-red); }
.admonition.danger  .admonition-title { background: rgba(179,27,27,.1); color: var(--accent-red); }
.admonition.info    { border-color: var(--accent-blue); }
.admonition.info    .admonition-title { background: rgba(50,135,208,.1); color: --accent-blue); }
.admonition.success { border-color: #4caf50; }
.admonition.success .admonition-title { background: rgba(76,175,80,.1); color: #4caf50; }


/* ===========================
   Document references (PDF / PPT)
   =========================== */
.doc-ref {
  margin: 1.5em 0;
  padding: 1rem;
  background: var(--bg-block);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  overflow: hidden;
}
.doc-ref-head {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}
.doc-ref-type {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--bg-color);
  background: var(--accent);
}
.doc-ref-page {
  color: var(--text-muted);
  font-size: 0.9rem;
}
.doc-ref iframe {
  display: block;
  width: 100%;
  min-height: 520px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background: var(--bg-color);
}
.ppt-ref p {
  margin: 0.5rem 0;
}

/* ===========================
   Innerlink card
   =========================== */
.innerlink-card {
  height: 200px;
  margin: 1em auto;
  position: relative;
  max-width: 780px;
  display: flex;
  background: var(--bg-block);
  border-radius: 15px;
  box-shadow: 0 2px 4px rgba(0,0,0,.1);
  overflow: hidden;
  transition: background 0.3s, box-shadow 0.3s;
}
.innerlink-card:hover {
  background: var(--bg-card);
  box-shadow: 0 4px 12px rgba(0,0,0,.15);
}
.innerlink-card a {
  display: block;
  padding: 1.5em;
  color: var(--text-color);
  text-decoration: none;
  width: 100%;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  font-size: 1.1rem;
  font-weight: 600;
}

/* ===========================
   Details / Collapsible
   =========================== */
details {
  margin: 1.2em 0;
  background: var(--bg-block);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
}
details[open] { border-color: var(--link-color); }
summary {
  padding: 0.75em 1em;
  cursor: pointer;
  font-weight: 600;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  color: var(--text-heading);
  user-select: none;
  list-style: none;
}
summary::before {
  content: '▶';
  display: inline-block;
  margin-right: 0.5em;
  font-size: 0.75rem;
  transition: transform 0.2s;
}
details[open] summary::before {
  transform: rotate(90deg);
}
details > :not(summary) {
  padding: 0.5em 1em 1em;
  border-top: 1px solid var(--border-light);
}

/* ===========================
   Search link styles
   =========================== */
.search-wiki, .search-arxiv, .search-github, .search-google {
  color: var(--link-color);
  text-decoration: none;
  border-bottom: 1px dashed var(--link-underline);
  transition: color 0.2s, border-color 0.2s;
}
.search-wiki:hover, .search-arxiv:hover,
.search-github:hover, .search-google:hover {
  color: var(--link-hover);
  border-bottom-color: var(--link-hover);
}
.search-arxiv { color: var(--arxiv-red); }
.search-arxiv:hover { color: #d11; }
.search-github { color: #24292e; }
html.dark .search-github { color: #c9d1d9; }
.search-google { color: var(--accent-blue); }

/* ===========================
   Internal jump links
   =========================== */
.jump-internal {
  color: var(--link-color);
  text-decoration: none;
  border-bottom: 1px solid var(--link-underline);
}
.jump-internal:hover {
  color: var(--link-hover);
  border-bottom-color: var(--link-hover);
}

/* ===========================
   Douban preview card
   =========================== */
.douban_show { margin: 1.5em 0; }
.douban_item {
  max-width: 780px;
  height: 200px;
  margin: 1em auto;
  position: relative;
  display: flex;
  background: var(--bg-card);
  border-radius: 15px;
  box-shadow: 0 2px 4px rgba(0,0,0,.1);
  overflow: hidden;
}
.douban_item:hover { box-shadow: 0 4px 12px rgba(0,0,0,.15); }
.douban_item--meta { width: 80%; padding: 23px; overflow: hidden; }
.douban_item--title { font-size: 1.3rem; margin: 0 0 8px; }
.douban_item--title a { color: var(--text-heading); text-decoration: none; }
.douban_item--title a:hover { color: var(--link-color); }
.douban_item--excerpt { font-size: 0.88rem; color: var(--text-muted); line-height: 1.6; max-height: 4em; overflow: hidden; }
.douban_item--image {
  width: 25%;
  background-size: cover;
  background-position: center;
  border-radius: 0 15px 15px 0;
}
.douban_item--date { font-size: 0.8rem; color: var(--text-muted); margin-top: 6px; }
/* ===========================
   Responsive embed helpers
   =========================== */
@media (max-width: 768px) {
  .bilibili-embed iframe,
  .youtube-embed lite-youtube { width: 100%; }
}

/* ===========================
   Prism.js Code Highlighting
   =========================== */
pre {
  background: var(--bg-code) !important;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.2rem 1.5rem !important;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.6;
  margin: 1.5rem 0;
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace !important;
}
pre code {
  background: none !important;
  padding: 0 !important;
  font-size: inherit;
  border: none !important;
  border-radius: 0 !important;
  color: inherit !important;
}
code {
  background: var(--bg-code);
  padding: 0.15em 0.45em;
  border-radius: 4px;
  font-size: 0.88em;
  font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  color: var(--accent-red);
  border: 1px solid var(--border-light);
}
html.dark code { color: #e57373; }

/* Inline code in headings - no bg */
h1 code, h2 code, h3 code, h4 code {
  background: none;
  border: none;
  padding: 0;
  font-size: 0.85em;
  color: inherit;
}

/* Language label on code blocks */
pre[class*="language-"]::before,
pre[class*="lang-"]::before {
  content: attr(data-lang);
  position: absolute;
  top: 0.5rem;
  right: 0.8rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
}

/* Dark mode code adjustments */
html.dark pre {
  background: #1e1e1e !important;
  border-color: #333;
}
html.dark code {
  background: #2d2d2d;
  color: #e06c75;
}

/* Bright mode code adjustments — override prism-tomorrow's light text */
html:not(.dark) pre,
html:not(.dark) pre code {
  color: #24292e !important;
}
html:not(.dark) code {
  color: #a01c1c;
}

/* ===========================
   Multi-language Code Tabs
   =========================== */
.code-tabs {
  margin: 1.5rem 0;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  background: var(--bg-code);
}

/* Tab header bar */
.code-tabs-header {
  display: flex;
  align-items: center;
  gap: 0;
  padding: 0 0.5rem;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-block);
}

.code-tab-btn {
  padding: 0.5rem 1rem;
  border: none;
  background: none;
  color: var(--text-muted);
  font-size: 0.82rem;
  font-family: 'LXGW Marker Gothic', system-ui, sans-serif;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
  white-space: nowrap;
  margin-bottom: -1px;
}

.code-tab-btn:hover {
  color: var(--text-color);
}

.code-tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* Tab content panels */
.code-tab-content {
  display: none;
}

.code-tab-content.active {
  display: block;
}

/* Reset pre margin inside tabs */
.code-tabs pre {
  margin: 0 !important;
  border: none !important;
  border-radius: 0 !important;
}

/* Hub tabs reuse the same tab switcher for graph/cards/list sections. */
.code-tabs.hub-tabs {
  background: var(--bg-block);
}

.hub-tabs .code-tab-content {
  padding: 1.25rem;
}

.hub-tabs .code-tab-content > :first-child {
  margin-top: 0;
}

.hub-tabs .code-tab-content > :last-child {
  margin-bottom: 0;
}

/* Dark mode tab adjustments */
html.dark .code-tabs-header {
  background: #2a241d;
}

html.dark .code-tab-btn.active {
  color: var(--accent-gold);
  border-bottom-color: var(--accent-gold);
}


/* ===========================
   Category Color System
   =========================== */
/* Light mode category colors */
.meta-tag[data-cat="历史"],
.meta-tag[data-cat='历史'] {
  background: rgba(180, 130, 60, 0.15);
  color: #8b6914;
  border-color: rgba(180, 130, 60, 0.3);
}
.meta-tag[data-cat="历史"]:hover {
  background: rgba(180, 130, 60, 0.25);
}
.article-footer a[data-cat="历史"] {
  color: #8b6914;
}

.meta-tag[data-cat="AI"],
.meta-tag[data-cat='AI'],
.meta-tag[data-cat="AI Research"],
.meta-tag[data-cat='AI Research'] {
  background: rgba(50, 135, 208, 0.12);
  color: #2a6cb8;
  border-color: rgba(50, 135, 208, 0.3);
}
.meta-tag[data-cat="AI"]:hover,
.meta-tag[data-cat='AI Research']:hover {
  background: rgba(50, 135, 208, 0.2);
}
.article-footer a[data-cat="AI"],
.article-footer a[data-cat='AI Research'] {
  color: #2a6cb8;
}

.meta-tag[data-cat="研究雷达"],
.meta-tag[data-cat='研究雷达'] {
  background: rgba(20, 150, 130, 0.12);
  color: #14867a;
  border-color: rgba(20, 150, 130, 0.3);
}
.meta-tag[data-cat="研究雷达"]:hover {
  background: rgba(20, 150, 130, 0.2);
}
.article-footer a[data-cat="研究雷达"] {
  color: #14867a;
}

.meta-tag[data-cat="方法论"],
.meta-tag[data-cat='方法论'] {
  background: rgba(90, 140, 80, 0.12);
  color: #4a7a3e;
  border-color: rgba(90, 140, 80, 0.3);
}
.meta-tag[data-cat="方法论"]:hover {
  background: rgba(90, 140, 80, 0.2);
}
.article-footer a[data-cat="方法论"] {
  color: #4a7a3e;
}

.meta-tag[data-cat="哲学"],
.meta-tag[data-cat='哲学'] {
  background: rgba(120, 80, 160, 0.12);
  color: #7a4ca0;
  border-color: rgba(120, 80, 160, 0.3);
}
.meta-tag[data-cat="哲学"]:hover {
  background: rgba(120, 80, 160, 0.2);
}
.article-footer a[data-cat="哲学"] {
  color: #7a4ca0;
}

.meta-tag[data-cat="行业研究"],
.meta-tag[data-cat='行业研究'] {
  background: rgba(180, 100, 60, 0.12);
  color: #a06030;
  border-color: rgba(180, 100, 60, 0.3);
}
.meta-tag[data-cat="行业研究"]:hover {
  background: rgba(180, 100, 60, 0.2);
}
.article-footer a[data-cat="行业研究"] {
  color: #a06030;
}

.meta-tag[data-cat="研究综述"],
.meta-tag[data-cat='研究综述'] {
  background: rgba(139, 94, 52, 0.15);
  color: #7a5a2e;
  border-color: rgba(139, 94, 52, 0.3);
}
.meta-tag[data-cat="研究综述"]:hover {
  background: rgba(139, 94, 52, 0.25);
}
.article-footer a[data-cat="研究综述"] {
  color: #7a5a2e;
}

.meta-tag[data-cat="软件"],
.meta-tag[data-cat='软件'] {
  background: rgba(100, 110, 130, 0.12);
  color: #5a6478;
  border-color: rgba(100, 110, 130, 0.3);
}
.meta-tag[data-cat="软件"]:hover {
  background: rgba(100, 110, 130, 0.2);
}
.article-footer a[data-cat="软件"] {
  color: #5a6478;
}

/* Dark mode category colors */
html.dark .meta-tag[data-cat="历史"],
html.dark .meta-tag[data-cat='历史'] {
  background: rgba(224, 180, 80, 0.15);
  color: #e0b450;
  border-color: rgba(224, 180, 80, 0.25);
}
html.dark .meta-tag[data-cat="历史"]:hover {
  background: rgba(224, 180, 80, 0.25);
}
html.dark .article-footer a[data-cat="历史"] {
  color: #e0b450;
}

html.dark .meta-tag[data-cat="AI"],
html.dark .meta-tag[data-cat='AI'],
html.dark .meta-tag[data-cat="AI Research"],
html.dark .meta-tag[data-cat='AI Research'] {
  background: rgba(96, 165, 250, 0.15);
  color: #60a5fa;
  border-color: rgba(96, 165, 250, 0.25);
}
html.dark .meta-tag[data-cat="AI"]:hover,
html.dark .meta-tag[data-cat='AI Research']:hover {
  background: rgba(96, 165, 250, 0.25);
}
html.dark .article-footer a[data-cat="AI"],
html.dark .article-footer a[data-cat='AI Research'] {
  color: #60a5fa;
}

html.dark .meta-tag[data-cat="研究雷达"],
html.dark .meta-tag[data-cat='研究雷达'] {
  background: rgba(52, 211, 180, 0.12);
  color: #34d3b4;
  border-color: rgba(52, 211, 180, 0.25);
}
html.dark .meta-tag[data-cat="研究雷达"]:hover {
  background: rgba(52, 211, 180, 0.2);
}
html.dark .article-footer a[data-cat="研究雷达"] {
  color: #34d3b4;
}

html.dark .meta-tag[data-cat="方法论"],
html.dark .meta-tag[data-cat='方法论'] {
  background: rgba(110, 180, 100, 0.12);
  color: #6eb464;
  border-color: rgba(110, 180, 100, 0.25);
}
html.dark .meta-tag[data-cat="方法论"]:hover {
  background: rgba(110, 180, 100, 0.2);
}
html.dark .article-footer a[data-cat="方法论"] {
  color: #6eb464;
}

html.dark .meta-tag[data-cat="哲学"],
html.dark .meta-tag[data-cat='哲学'] {
  background: rgba(180, 140, 220, 0.12);
  color: #b48cdc;
  border-color: rgba(180, 140, 220, 0.25);
}
html.dark .meta-tag[data-cat="哲学"]:hover {
  background: rgba(180, 140, 220, 0.2);
}
html.dark .article-footer a[data-cat="哲学"] {
  color: #b48cdc;
}

html.dark .meta-tag[data-cat="行业研究"],
html.dark .meta-tag[data-cat='行业研究'] {
  background: rgba(230, 150, 90, 0.12);
  color: #e0965a;
  border-color: rgba(230, 150, 90, 0.25);
}
html.dark .meta-tag[data-cat="行业研究"]:hover {
  background: rgba(230, 150, 90, 0.2);
}
html.dark .article-footer a[data-cat="行业研究"] {
  color: #e0965a;
}

html.dark .meta-tag[data-cat="研究综述"],
html.dark .meta-tag[data-cat='研究综述'] {
  background: rgba(212, 167, 106, 0.15);
  color: #d4a76a;
  border-color: rgba(212, 167, 106, 0.25);
}
html.dark .meta-tag[data-cat="研究综述"]:hover {
  background: rgba(212, 167, 106, 0.25);
}
html.dark .article-footer a[data-cat="研究综述"] {
  color: #d4a76a;
}

html.dark .meta-tag[data-cat="软件"],
html.dark .meta-tag[data-cat='软件'] {
  background: rgba(160, 170, 190, 0.12);
  color: #a0aabe;
  border-color: rgba(160, 170, 190, 0.25);
}
html.dark .meta-tag[data-cat="软件"]:hover {
  background: rgba(160, 170, 190, 0.2);
}
html.dark .article-footer a[data-cat="软件"] {
  color: #a0aabe;
}
/* Cross-reference links */
a.xref { color: var(--accent-blue); border-bottom: 1px dashed var(--accent-blue); }
a.xref:hover { color: var(--accent); border-bottom-style: solid; }


/* ===========================
   Document page shortcode (PDF.js on demand)
   =========================== */
.doc-page {
  margin: 1.6rem auto;
  border: 1px solid var(--border-color);
  border-radius: 16px;
  background: var(--bg-card);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}

/* docref is intentionally compact: an enhanced source link, not a preview block. */
.doc-ref {
  margin: 0.55rem 0;
  padding: 0.5rem 0.65rem;
  border: 1px solid var(--border-light);
  border-left: 3px solid var(--accent);
  border-radius: 10px;
  background: color-mix(in srgb, var(--bg-card) 64%, transparent);
  box-shadow: none;
  overflow: hidden;
}

.doc-page-head {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1rem;
  background: linear-gradient(135deg, rgba(139, 94, 52, 0.10), rgba(212, 160, 23, 0.08));
  border-bottom: 1px solid var(--border-light);
}

.doc-ref-head {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  margin: 0;
  flex-wrap: wrap;
}

.doc-page-head span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 3rem;
  padding: 0.15rem 0.45rem;
  border-radius: 999px;
  background: var(--accent);
  color: var(--hero-text);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.doc-ref-type {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2.4rem;
  padding: 0.08rem 0.35rem;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 82%, transparent);
  color: var(--hero-text);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.doc-page-head strong { flex: 1; color: var(--text-heading); }
.doc-ref-head strong { flex: 1; color: var(--text-heading); font-size: 0.95rem; }

.doc-page-head em {
  color: var(--text-muted);
  font-style: normal;
  font-size: 0.9rem;
}

.doc-ref-page { color: var(--text-muted); font-size: 0.82rem; }
.doc-ref-source { color: var(--text-muted); font-size: 0.82rem; margin: 0.15rem 0 0; }
.doc-ref .caption { margin: 0.15rem 0 0; font-size: 0.85rem; text-align: left; }

.doc-page-stage {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 1rem;
  background: color-mix(in srgb, var(--bg-body) 70%, var(--bg-card));
  overflow-x: auto;
}

.doc-page-canvas canvas {
  display: block;
  max-width: 100%;
  height: auto;
  border-radius: 10px;
  background: white;
  box-shadow: 0 8px 24px rgba(0,0,0,0.18);
}

.doc-page-loading {
  position: absolute;
  inset: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  background: rgba(255,255,255,0.55);
  border-radius: 10px;
  pointer-events: none;
}

html.dark .doc-page-loading { background: rgba(0,0,0,0.32); }

.doc-page.is-rendered .doc-page-loading { display: none; }

.doc-page iframe { display: block; background: var(--bg-body); }

.doc-page figcaption {
  padding: 0.75rem 1rem 1rem;
  color: var(--text-muted);
  font-size: 0.92rem;
  text-align: center;
}

.doc-pages { margin: 1.5rem 0; }


/* ===========================
   Hub Page Components
   =========================== */

/* === Hub 布局 === */
.hub-section { margin: 3rem 0; }
.hub-section .section-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 1.2rem;
  color: var(--accent);
  border-left: 4px solid var(--accent);
  padding-left: 1rem;
}

/* === Period Grid (历史叙事、专题索引) === */
.period-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; }
@media (max-width: 768px) { .period-grid { grid-template-columns: 1fr; } }

.period-card {
  background: var(--bg-card, rgba(255,255,255,0.04));
  border: 1px solid var(--border-color, rgba(255,255,255,0.08));
  border-radius: 12px;
  padding: 1.5rem;
  transition: all 0.3s ease;
}
.period-card:hover {
  background: color-mix(in srgb, var(--accent) 8%, var(--bg-card));
  border-color: var(--accent);
  transform: translateY(-2px);
}
.period-card .period-years {
  font-size: 0.85rem;
  color: var(--accent-gold);
  font-weight: 600;
  letter-spacing: 1px;
}
.period-card .period-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0.4rem 0;
  color: var(--text-heading);
}
.period-card .period-teaser {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0.6rem 0 0.8rem;
}
.period-card .period-question {
  font-size: 0.85rem;
  color: var(--accent);
  font-style: italic;
  border-top: 1px solid var(--border-color);
  padding-top: 0.6rem;
  margin-top: 0.6rem;
}
.period-card .period-link {
  font-size: 0.85rem;
  color: var(--accent);
  text-decoration: none;
}
.period-card .period-link:hover { text-decoration: underline; }

/* === Chapter List (教程、书籍章节) === */
.chapter-list { list-style: none; padding: 0; }
.chapter-list li {
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 0.8rem;
}
.chapter-list li:last-child { border-bottom: none; }

.chapter-list .chapter-num {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
  min-width: 2rem;
  font-family: 'JetBrains Mono', monospace;
}
.chapter-list .chapter-title { flex: 1; }
.chapter-list .chapter-title a {
  color: var(--text-heading);
  text-decoration: none;
  transition: color 0.2s;
}
.chapter-list .chapter-title a:hover { color: var(--accent); }

.chapter-list .chapter-status {
  font-size: 0.75rem;
  padding: 0.15rem 0.5rem;
  border-radius: 12px;
  font-weight: 500;
}
.chapter-list .chapter-status.done {
  background: color-mix(in srgb, var(--accent-green, #4ec9b0) 15%, transparent);
  color: var(--accent-green, #4ec9b0);
}
.chapter-list .chapter-status.todo {
  background: color-mix(in srgb, var(--text-muted) 15%, transparent);
  color: var(--text-muted);
}

/* === Topic List === */
.topic-list { list-style: none; padding: 0; }
.topic-list li { padding: 0.3rem 0; font-size: 0.95rem; color: var(--text-secondary); }
.topic-list li::before { content: "→ "; color: var(--accent); }
.topic-list li.done { color: var(--accent-gold); }
.topic-list li.done::before { content: "✅ "; }
.topic-list li.research { color: var(--accent-red); }
.topic-list li.research::before { content: "🔬 "; }