:root {
  --bg: #0f1117;
  --bg-elev: #161923;
  --bg-code: #12151d;
  --border: #262b3a;
  --text: #d7dbe6;
  --text-dim: #8b93a7;
  --heading: #f2f4fa;
  --accent: #7c8cff;
  --accent-soft: rgba(124, 140, 255, 0.14);
  --mark: rgba(255, 207, 77, 0.28);
  --tok-c: #6b7490;
  --tok-s: #a5d68a;
  --tok-n: #f2a87a;
  --tok-k: #c59bff;
  --tok-t: #6fd0e8;
  --tok-f: #8fb4ff;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  --topbar-h: 58px;
  --sidebar-w: 280px;
}

:root[data-theme='light'] {
  --bg: #ffffff;
  --bg-elev: #f6f7fb;
  --bg-code: #f4f5fa;
  --border: #e3e6ef;
  --text: #2b3040;
  --text-dim: #6a7288;
  --heading: #0f1320;
  --accent: #4455e0;
  --accent-soft: rgba(68, 85, 224, 0.1);
  --mark: rgba(255, 196, 0, 0.35);
  --tok-c: #8890a6;
  --tok-s: #2f8a3c;
  --tok-n: #c2561a;
  --tok-k: #8a3fd1;
  --tok-t: #0f7f9b;
  --tok-f: #2f5fd0;
  --shadow: 0 20px 60px rgba(20, 30, 70, 0.18);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--topbar-h) + 18px); }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, 'Segoe UI', Inter, Roboto, 'Helvetica Neue', Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
kbd {
  font: 11px/1 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  padding: 3px 6px;
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 5px;
  background: var(--bg-elev);
  color: var(--text-dim);
}

/* ---------- topbar ---------- */
.topbar {
  position: fixed; inset: 0 0 auto 0; height: var(--topbar-h); z-index: 50;
  display: flex; align-items: center; gap: 14px; padding: 0 20px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--heading); text-decoration: none; font-weight: 700; font-size: 17px; white-space: nowrap; }
.logo { color: var(--accent); font-size: 20px; }
.search-btn {
  margin-left: 24px; flex: 0 1 380px; display: flex; align-items: center; gap: 10px;
  padding: 8px 12px; color: var(--text-dim); cursor: pointer; text-align: left;
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: 10px; font: inherit; font-size: 14px;
}
.search-btn:hover { border-color: var(--accent); }
.search-btn .s-label { flex: 1; }
.s-ico { font-size: 17px; }
.actions { margin-left: auto; display: flex; align-items: center; gap: 8px; }
.btn, .icon-btn {
  font: inherit; font-size: 14px; cursor: pointer; color: var(--text);
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: 9px; padding: 7px 13px;
}
.btn:hover, .icon-btn:hover { border-color: var(--accent); }
.btn.ghost { background: transparent; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }
.icon-btn { padding: 6px 10px; font-size: 16px; }
.menu-btn { display: none; }

/* ---------- layout ---------- */
.layout { display: flex; padding-top: var(--topbar-h); }
.sidebar {
  position: sticky; top: var(--topbar-h); align-self: flex-start;
  width: var(--sidebar-w); flex: 0 0 var(--sidebar-w);
  height: calc(100vh - var(--topbar-h)); overflow-y: auto;
  padding: 22px 12px 40px 20px; border-right: 1px solid var(--border);
}
.main { flex: 1; min-width: 0; padding: 36px 48px 60px; }
.prose { max-width: 860px; margin: 0 auto; }
.footer { max-width: 860px; margin: 56px auto 0; padding-top: 18px; border-top: 1px solid var(--border); color: var(--text-dim); font-size: 13px; }
.scrim { display: none; }

/* ---------- nav ---------- */
.nav-title { font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-dim); margin: 0 0 10px 10px; }
.nav-group { margin-bottom: 2px; }
.nav-h2, .nav-h3 {
  display: block; text-decoration: none; color: var(--text-dim);
  padding: 6px 10px; border-radius: 8px; font-size: 14px; line-height: 1.4;
  border-left: 2px solid transparent;
}
.nav-h2 { font-weight: 600; color: var(--text); }
.nav-h3 { margin-left: 12px; font-size: 13px; padding: 4px 10px; }
.nav-h2:hover, .nav-h3:hover { background: var(--bg-elev); color: var(--heading); }
.nav-h2.active, .nav-h3.active { color: var(--accent); background: var(--accent-soft); border-left-color: var(--accent); }
.nav-sub { display: none; }
.nav-group.open .nav-sub { display: block; }

/* ---------- prose ---------- */
.prose h1, .prose h2, .prose h3, .prose h4 { color: var(--heading); line-height: 1.25; position: relative; }
.prose h1 { font-size: 2.4rem; margin: 0 0 18px; letter-spacing: -0.02em; }
.prose h2 { font-size: 1.65rem; margin: 3rem 0 14px; padding-top: 1.6rem; border-top: 1px solid var(--border); letter-spacing: -0.01em; }
.prose h1 + p { font-size: 1.1rem; color: var(--text-dim); }
.prose h3 { font-size: 1.2rem; margin: 2rem 0 10px; }
.prose h4 { font-size: 1.05rem; margin: 1.6rem 0 8px; }
.prose .anchor { position: absolute; left: -1.1em; color: var(--accent); text-decoration: none; opacity: 0; font-weight: 400; }
.prose h1:hover .anchor, .prose h2:hover .anchor, .prose h3:hover .anchor, .prose h4:hover .anchor { opacity: 0.7; }
.prose p { margin: 0 0 1.1em; }
.prose a { color: var(--accent); }
.prose ul, .prose ol { padding-left: 1.5em; margin: 0 0 1.1em; }
.prose li { margin: 0.25em 0; }
.prose hr { border: 0; border-top: 1px solid var(--border); margin: 2rem 0; }
.prose img { max-width: 100%; border-radius: 8px; }
.prose blockquote { margin: 0 0 1.1em; padding: 4px 18px; border-left: 3px solid var(--accent); background: var(--accent-soft); border-radius: 0 8px 8px 0; color: var(--text); }
.prose blockquote > :last-child { margin-bottom: 0; }
.prose code {
  font: 0.86em ui-monospace, SFMono-Regular, 'JetBrains Mono', Menlo, Consolas, monospace;
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: 6px; padding: 1px 6px;
  overflow-wrap: anywhere;
}

/* code blocks */
.code { margin: 0 0 1.4em; border: 1px solid var(--border); border-radius: 12px; overflow: hidden; background: var(--bg-code); }
.code-head { display: flex; justify-content: space-between; align-items: center; padding: 7px 14px; border-bottom: 1px solid var(--border); font-size: 12px; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.06em; }
.copy { font: inherit; font-size: 12px; text-transform: none; letter-spacing: 0; cursor: pointer; color: var(--text-dim); background: transparent; border: 1px solid var(--border); border-radius: 6px; padding: 2px 9px; }
.copy:hover { color: var(--heading); border-color: var(--accent); }
.prose pre { margin: 0; padding: 16px 18px; overflow-x: auto; }
.prose pre code { background: none; border: 0; padding: 0; font-size: 13.5px; line-height: 1.6; overflow-wrap: normal; white-space: pre; }
.tok-c { color: var(--tok-c); font-style: italic; }
.tok-s { color: var(--tok-s); }
.tok-n { color: var(--tok-n); }
.tok-k { color: var(--tok-k); }
.tok-t { color: var(--tok-t); }
.tok-f { color: var(--tok-f); }

/* tables */
.table-wrap { overflow-x: auto; margin: 0 0 1.4em; border: 1px solid var(--border); border-radius: 12px; }
.prose table { border-collapse: collapse; width: 100%; font-size: 14.5px; }
.prose th { text-align: left; background: var(--bg-elev); color: var(--heading); font-weight: 600; white-space: nowrap; }
.prose th, .prose td { padding: 10px 14px; border-bottom: 1px solid var(--border); vertical-align: top; }
.prose tr:last-child td { border-bottom: 0; }
.prose td:first-child { white-space: nowrap; }
.prose tbody tr:hover { background: var(--accent-soft); }
.prose td code { font-size: 0.85em; }

/* ---------- dialogs ---------- */
.dlg { border: 1px solid var(--border); border-radius: 14px; background: var(--bg-elev); color: var(--text); box-shadow: var(--shadow); padding: 0; }
.dlg::backdrop { background: rgba(5, 8, 15, 0.6); backdrop-filter: blur(3px); }
.search-dlg { width: min(640px, 92vw); margin-top: 12vh; }
.search-dlg input { width: 100%; padding: 16px 18px; font: inherit; font-size: 17px; color: var(--heading); background: transparent; border: 0; border-bottom: 1px solid var(--border); outline: 0; }
.results { list-style: none; margin: 0; padding: 8px; max-height: 50vh; overflow-y: auto; }
.results li { padding: 10px 12px; border-radius: 9px; cursor: pointer; }
.results li.sel, .results li:hover { background: var(--accent-soft); }
.r-title { color: var(--heading); font-weight: 600; font-size: 14.5px; }
.r-crumb { color: var(--text-dim); font-weight: 400; }
.r-snip { color: var(--text-dim); font-size: 13px; line-height: 1.5; margin-top: 2px; }
.results mark, .r-title mark { background: var(--mark); color: inherit; border-radius: 3px; }
.results .empty { color: var(--text-dim); cursor: default; text-align: center; padding: 22px; }
.dlg-foot { display: flex; gap: 18px; padding: 9px 16px; border-top: 1px solid var(--border); color: var(--text-dim); font-size: 12px; }
.dlg-foot kbd { margin-right: 4px; }



/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .menu-btn { display: inline-block; }
  .sidebar { position: fixed; left: 0; top: var(--topbar-h); z-index: 45; background: var(--bg); transform: translateX(-100%); transition: transform 0.22s; width: min(300px, 84vw); }
  body.nav-open .sidebar { transform: none; }
  body.nav-open .scrim { display: block; position: fixed; inset: var(--topbar-h) 0 0 0; z-index: 40; background: rgba(0, 0, 0, 0.5); }
  .main { padding: 24px 18px 50px; }
  .search-btn { margin-left: 0; }
  .search-btn kbd { display: none; }
  .prose h1 { font-size: 1.9rem; }
  .prose .anchor { display: none; }
}
@media (max-width: 560px) {
  .brand span:last-child { display: none; }
  .btn { padding: 6px 10px; }
}