:root {
  --bg: #ffffff;
  --bg2: #f7f8fa;
  --bg3: #eef0f3;
  --ink: #1a1d21;
  --muted: #5b6470;
  --faint: #8a929e;
  --line: #e3e6ea;
  --accent: #2b6df3;
  --accent-soft: rgba(43, 109, 243, 0.08);
  --code-bg: #f2f4f7;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color-scheme: light;
}

html[data-theme="dark"] {
  --bg: #0d1117;
  --bg2: #11161d;
  --bg3: #161d26;
  --ink: #d7dee7;
  --muted: #9aa5b1;
  --faint: #6b7683;
  --line: #242c36;
  --accent: #6ea8ff;
  --accent-soft: rgba(110, 168, 255, 0.1);
  --code-bg: #161c24;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.75;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.layout { display: flex; min-height: 100dvh; }

/* ── 侧边栏 ───────────────────────────── */
.sidebar {
  width: 280px;
  flex: none;
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--line);
  background: var(--bg2);
  position: sticky;
  top: 0;
  height: 100dvh;
}
.side-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
}
.brand { font-weight: 700; color: var(--ink); font-size: 15px; }
.brand:hover { text-decoration: none; }
.theme-btn {
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 4px 8px;
  cursor: pointer;
  color: var(--muted);
  font-size: 13px;
}
.theme-btn:hover { color: var(--ink); border-color: var(--muted); }
.side-body {
  flex: 1;
  overflow-y: auto;
  padding: 10px 8px 20px;
}
.side-body details { margin: 2px 0; }
.side-body summary {
  cursor: pointer;
  padding: 6px 10px;
  font-size: 12px;
  font-weight: 600;
  color: var(--faint);
  letter-spacing: 0.04em;
  user-select: none;
}
.side-body summary:hover { color: var(--ink); }
.side-body ul { list-style: none; margin: 0 0 6px; padding: 0; }
.side-body li a {
  display: block;
  padding: 5px 10px 5px 20px;
  color: var(--muted);
  font-size: 13.5px;
  border-left: 2px solid transparent;
}
.side-body li a:hover { color: var(--ink); text-decoration: none; background: var(--bg3); }
.side-body li a.active {
  color: var(--accent);
  border-left-color: var(--accent);
  background: var(--accent-soft);
}
.side-foot {
  padding: 10px 16px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  color: var(--faint);
}

/* ── 内容区 ───────────────────────────── */
.content {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}
.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 24px;
  border-bottom: 1px solid var(--line);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 20;
}
.menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 4px 10px;
  cursor: pointer;
  color: var(--ink);
}
.search-wrap { position: relative; flex: 1; max-width: 460px; }
.search-wrap input {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg2);
  color: var(--ink);
  font: inherit;
  font-size: 13.5px;
  outline: none;
}
.search-wrap input:focus { border-color: var(--accent); }
.search-results {
  position: absolute;
  left: 0;
  right: 0;
  top: calc(100% + 6px);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.14);
  max-height: 360px;
  overflow-y: auto;
  z-index: 30;
}
.search-results a {
  display: block;
  padding: 9px 12px;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
}
.search-results a:last-child { border-bottom: 0; }
.search-results a:hover { background: var(--bg3); text-decoration: none; }
.search-results .t { font-weight: 600; font-size: 13.5px; }
.search-results .s { font-size: 11px; color: var(--faint); margin-left: 8px; }
.search-results .b { font-size: 12px; color: var(--muted); display: block; margin-top: 2px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.search-empty { padding: 14px; font-size: 13px; color: var(--faint); }
.crumb { font-size: 12px; color: var(--faint); white-space: nowrap; margin-left: auto; }

.doc {
  max-width: 860px;
  width: 100%;
  margin: 0 auto;
  padding: 32px 28px 64px;
}
.doc h1 {
  font-size: 30px;
  line-height: 1.3;
  margin: 0 0 8px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}
.doc h2 {
  font-size: 21px;
  margin: 34px 0 12px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--line);
}
.doc h3 { font-size: 17px; margin: 26px 0 10px; }
.doc h4 { font-size: 15px; margin: 20px 0 8px; }
.doc p { margin: 10px 0; }
.doc ul, .doc ol { margin: 10px 0; padding-left: 24px; }
.doc li { margin: 4px 0; }
.doc blockquote {
  margin: 14px 0;
  padding: 10px 14px;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 6px 6px 0;
  color: var(--muted);
}
.doc blockquote p { margin: 4px 0; }
.doc code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--code-bg);
  border-radius: 4px;
  padding: 1px 5px;
}
.doc pre {
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 16px;
  overflow-x: auto;
  line-height: 1.55;
}
.doc pre code { background: none; padding: 0; }
.doc table {
  width: 100%;
  border-collapse: collapse;
  margin: 0;
  font-size: 13.5px;
  display: table;
  max-width: 100%;
}
.table-wrap {
  overflow-x: auto;
  margin: 16px 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg);
}
.doc th, .doc td {
  border: 1px solid var(--line);
  padding: 8px 10px;
  text-align: left;
  white-space: normal;
  vertical-align: top;
}
.doc th { background: var(--bg2); font-weight: 600; white-space: nowrap; }
.doc img { max-width: 100%; border-radius: 8px; }
.doc hr { border: 0; border-top: 1px solid var(--line); margin: 24px 0; }

.doc-foot {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 48px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 14px;
}
.doc-foot a { color: var(--ink); font-weight: 600; }
.doc-foot a:hover { color: var(--accent); }

.index .idx-group { margin: 26px 0; }
.index .idx-group h2 {
  border-bottom: 1px solid var(--line);
  padding-bottom: 6px;
  font-size: 17px;
}
.index .idx-group ul {
  columns: 2;
  list-style: none;
  padding: 0;
  margin: 10px 0;
}
.index .idx-group li { margin: 5px 0; }
.index .idx-note { margin-top: 40px; font-weight: 600; }

@media (max-width: 900px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    z-index: 40;
    transform: translateX(-100%);
    transition: transform 0.18s ease;
    box-shadow: 8px 0 30px rgba(0, 0, 0, 0.16);
  }
  body.nav-open .sidebar { transform: translateX(0); }
  .menu-btn { display: block; }
  .doc { padding: 20px 18px 48px; }
  .doc table { font-size: 12.5px; }
  .index .idx-group ul { columns: 1; }
}