:root {
  --bg: #f6f7fb;
  --panel: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #d9dee8;
  --primary: #2563eb;
  --primary-soft: #e8f0ff;
  --code: #f3f4f6;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
.topbar {
  background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 58%, #38bdf8 100%);
  color: #fff;
  padding: 34px max(24px, calc((100vw - 1180px) / 2 + 24px));
}
.topbar h1 { margin: 4px 0 8px; font-size: 34px; line-height: 1.2; }
.topbar p { max-width: 900px; margin: 0; color: rgba(255, 255, 255, 0.9); }
.eyebrow { font-size: 13px; letter-spacing: .12em; text-transform: uppercase; }
.shell {
  max-width: 1180px;
  margin: 24px auto 64px;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 22px;
}
.sidebar {
  position: sticky;
  top: 20px;
  align-self: start;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--panel);
  box-shadow: 0 12px 32px rgba(15, 23, 42, 0.08);
}
.sidebar strong { display: block; margin-bottom: 10px; }
.sidebar a {
  display: block;
  padding: 8px 10px;
  border-radius: 10px;
  color: var(--text);
}
.sidebar a:hover,
.sidebar a.active {
  background: var(--primary-soft);
  color: var(--primary);
  text-decoration: none;
}
.notice {
  margin-top: 14px;
  padding: 10px;
  border-radius: 12px;
  background: #fff7ed;
  color: #7c2d12;
  font-size: 13px;
}
.content {
  min-width: 0;
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--panel);
  box-shadow: 0 12px 32px rgba(15, 23, 42, 0.08);
}
h1, h2, h3, h4 { line-height: 1.3; }
h1 { margin-top: 0; }
h2 {
  margin-top: 36px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}
h2:first-child { margin-top: 0; }
h3 { margin-top: 24px; }
blockquote {
  margin: 12px 0;
  padding: 12px 14px;
  border-left: 4px solid var(--primary);
  background: #f8fafc;
  color: var(--muted);
}
table {
  width: 100%;
  border-collapse: collapse;
  margin: 14px 0 20px;
  display: block;
  overflow-x: auto;
}
th, td {
  border: 1px solid var(--border);
  padding: 9px 11px;
  text-align: left;
  vertical-align: top;
}
th { background: #f8fafc; }
code {
  padding: 2px 5px;
  border-radius: 6px;
  background: var(--code);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: .92em;
}
pre {
  overflow-x: auto;
  padding: 16px;
  border-radius: 14px;
  background: #111827;
  color: #f9fafb;
}
pre code { padding: 0; background: transparent; color: inherit; }
hr { border: 0; border-top: 1px solid var(--border); margin: 26px 0; }
@media (max-width: 900px) {
  .shell { grid-template-columns: 1fr; }
  .sidebar { position: static; }
}
@media print {
  body { background: #fff; }
  .topbar, .sidebar, .content { box-shadow: none; }
  .shell { display: block; max-width: none; }
  .sidebar { display: none; }
}