:root {
  --bg: #0b1220;
  --bg-elev: #121a2b;
  --bg-soft: #182338;
  --border: #243049;
  --text: #e8eef9;
  
  --muted: #9aacc8;
  --accent: #4cc9f0;
  --accent2: #7bdff2;
  --accent-dim: rgba(76,201,240,.12);
  --ok: #6ee7a8;
  --warn: #fbbf24;
  --link: #8bd3ff;
  --sidebar-w: 280px;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(0,0,0,.25);
  --font: "Inter", "Noto Sans SC", "Noto Sans TC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}
[data-theme="light"] {
  --bg: #f6f8fc;
  --bg-elev: #ffffff;
  --bg-soft: #eef3fb;
  --border: #d7e0ef;
  --text: #152033;
  --muted: #5b6b86;
  --accent: #087ea4;
  --accent2: #0ea5e9;
  --accent-dim: rgba(8,126,164,.08);
  --link: #0369a1;
  --shadow: 0 10px 30px rgba(21,32,51,.08);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  background: radial-gradient(1200px 600px at 10% -10%, #1a2744 0%, transparent 55%),
              radial-gradient(900px 500px at 100% 0%, #142033 0%, transparent 45%),
              var(--bg);
  color: var(--text);
  line-height: 1.7;
  min-height: 100vh;
}
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
.layout { display: grid; grid-template-columns: var(--sidebar-w) 1fr; min-height: 100vh; }
.sidebar {
  position: sticky; top: 0; height: 100vh; overflow: auto;
  background: color-mix(in srgb, var(--bg-elev) 92%, transparent);
  border-right: 1px solid var(--border);
  padding: 18px 14px 28px;
  backdrop-filter: blur(10px);
}
.brand { display: flex; gap: 12px; align-items: center; padding: 8px 10px 18px; }
.brand-mark {
  width: 42px; height: 42px; border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), #4361ee);
  display: grid; place-items: center; font-weight: 800; color: #041018;
  box-shadow: var(--shadow);
}
.brand h1 { font-size: 1.05rem; margin: 0; line-height: 1.25; }
.brand p { margin: 2px 0 0; color: var(--muted); font-size: .78rem; }
.lang-switch, .toolbar {
  display: flex; gap: 6px; flex-wrap: wrap; padding: 0 10px 14px;
}
.lang-switch a, .tool-btn {
  border: 1px solid var(--border); background: var(--bg-soft);
  color: var(--text); border-radius: 999px; padding: 5px 10px; font-size: .78rem;
}
.lang-switch a.active {
  background: var(--accent-dim); border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
  color: var(--accent2); font-weight: 700; text-decoration: none;
}
.tool-btn { cursor: pointer; }
.search-wrap { padding: 0 10px 14px; }
.search-wrap input {
  width: 100%; border-radius: 10px; border: 1px solid var(--border);
  background: var(--bg); color: var(--text); padding: 10px 12px; outline: none;
}
.search-wrap input:focus { border-color: var(--accent); }
.nav-section { margin: 8px 6px; color: var(--muted); font-size: .72rem; letter-spacing: .08em; text-transform: uppercase; }
.nav a {
  display: block; padding: 8px 12px; border-radius: 10px; color: var(--text);
  text-decoration: none; font-size: .92rem; margin: 2px 4px;
}
.nav a:hover, .nav a.active { background: var(--accent-dim); color: var(--accent2); }
.main { padding: 28px 36px 80px; max-width: 1100px; }
.hero {
  background: linear-gradient(160deg, var(--bg-elev), var(--bg-soft));
  border: 1px solid var(--border); border-radius: calc(var(--radius) + 4px);
  padding: 28px; box-shadow: var(--shadow); margin-bottom: 24px;
}
.hero h2 { margin: 0 0 10px; font-size: clamp(1.6rem, 3vw, 2.2rem); line-height: 1.25; }
.hero p { margin: 0; color: var(--muted); max-width: 70ch; }
.badges { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.badge {
  font-size: .78rem; padding: 4px 10px; border-radius: 999px;
  background: var(--accent-dim); color: var(--accent2); border: 1px solid var(--border);
}
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 14px; margin: 18px 0 8px; }
.card {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px 16px 14px; transition: transform .15s ease, border-color .15s ease;
}
.card:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.card h3 { margin: 0 0 8px; font-size: 1.02rem; }
.card p { margin: 0; color: var(--muted); font-size: .92rem; }
.section { margin: 28px 0; }
.section h2 { margin: 0 0 12px; font-size: 1.45rem; }
.section h3 { margin: 22px 0 8px; font-size: 1.12rem; }
.section h4 { margin: 16px 0 6px; font-size: 1rem; color: var(--accent2); }
.prose p, .prose li { color: color-mix(in srgb, var(--text) 92%, var(--muted)); }
.prose ul, .prose ol { padding-left: 1.2rem; }
.prose li { margin: 4px 0; }
.callout {
  border-left: 3px solid var(--accent); background: var(--accent-dim);
  padding: 12px 14px; border-radius: 0 12px 12px 0; margin: 14px 0;
}
.table-wrap { overflow: auto; border: 1px solid var(--border); border-radius: 12px; margin: 12px 0; }
table { width: 100%; border-collapse: collapse; font-size: .92rem; }
th, td { padding: 10px 12px; border-bottom: 1px solid var(--border); text-align: left; vertical-align: top; }
th { background: var(--bg-soft); color: var(--accent2); white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
code, .mono { font-family: var(--mono); font-size: .88em; }
.tag {
  display: inline-block; font-size: .72rem; padding: 2px 8px; border-radius: 999px;
  background: var(--bg-soft); border: 1px solid var(--border); color: var(--muted); margin-right: 4px;
}
.sources { font-size: .88rem; color: var(--muted); }
.footer {
  margin-top: 40px; padding-top: 18px; border-top: 1px solid var(--border);
  color: var(--muted); font-size: .85rem;
}
.toc { background: var(--bg-elev); border: 1px solid var(--border); border-radius: 12px; padding: 14px 16px; }
.toc a { display: block; padding: 3px 0; }
.mobile-bar {
  display: none; position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 90%, transparent); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border); padding: 10px 14px; align-items: center; gap: 10px;
}
.hamburger {
  border: 1px solid var(--border); background: var(--bg-elev); color: var(--text);
  border-radius: 10px; padding: 8px 12px; cursor: pointer;
}
@media (max-width: 920px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed; inset: 0 auto 0 0; width: min(86vw, 320px); transform: translateX(-105%);
    transition: transform .2s ease; z-index: 30;
  }
  .sidebar.open { transform: translateX(0); }
  .mobile-bar { display: flex; }
  .main { padding: 18px 16px 60px; }
  .backdrop {
    display: none; position: fixed; inset: 0; background: rgba(0,0,0,.45); z-index: 25;
  }
  .backdrop.show { display: block; }
}
.sr-only { position:absolute; width:1px; height:1px; padding:0; margin:-1px; overflow:hidden; clip:rect(0,0,0,0); border:0; }