:root {
  --primary: #3b82f6;
  --primary-dark: #2563eb;
  --text: #1f2937;
  --muted: #6b7280;
  --bg: #ffffff;
  --surface: #f5f5f5;
  --border: #e5e5e5;
  --code-bg: #0f172a;
  --code-text: #e2e8f0;
}

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

body {
  font-family: "PingFang SC", "Microsoft YaHei", -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
}

.wrap { max-width: 960px; margin: 0 auto; padding: 0 20px; }

.topbar {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.topbar-inner { display: flex; align-items: center; justify-content: space-between; height: 56px; }
.brand { display: flex; align-items: center; gap: 8px; font-weight: 700; color: var(--text); text-decoration: none; }
.brand small { color: var(--muted); font-weight: 400; }
.brand-mark {
  display: inline-flex; align-items: center; justify-content: center;
  width: 28px; height: 28px; border-radius: 8px;
  background: var(--primary); color: #fff; font-size: 15px;
}
.nav { display: flex; gap: 4px; flex-wrap: wrap; }
.nav a { padding: 6px 10px; border-radius: 6px; color: var(--text); text-decoration: none; font-size: 14px; }
.nav a:hover { background: var(--surface); color: var(--primary-dark); }

.hero { padding: 72px 0 40px; text-align: center; }
.hero h1 { font-size: 40px; font-weight: 800; }
.hero .dim { color: var(--muted); font-weight: 400; }
.lead { margin: 16px auto 12px; max-width: 640px; color: var(--muted); font-size: 17px; }
.badges { margin: 8px 0 24px; }
.badge {
  display: inline-block; margin: 4px; padding: 3px 12px;
  border: 1px solid var(--border); border-radius: 999px;
  font-size: 13px; color: var(--muted); background: var(--surface);
}
.actions { display: flex; gap: 12px; justify-content: center; margin-top: 20px; }
.btn {
  display: inline-block; padding: 10px 24px; border-radius: 8px;
  border: 1px solid var(--primary); color: var(--primary); text-decoration: none; font-weight: 600;
}
.btn:hover { background: #eff6ff; }
.btn.primary { background: var(--primary); color: #fff; }
.btn.primary:hover { background: var(--primary-dark); }

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; padding: 24px 0 48px; }
.card {
  display: block; padding: 20px; border: 1px solid var(--border); border-radius: 12px;
  text-decoration: none; color: var(--text); background: #fff;
  transition: box-shadow .15s, transform .15s;
}
.card:hover { box-shadow: 0 6px 24px rgba(59,130,246,.12); transform: translateY(-2px); }
.card h3 { margin-bottom: 8px; font-size: 17px; }
.card p { color: var(--muted); font-size: 14px; }

/* ---- 内容页 ---- */
.page { padding: 40px 0 64px; }
.page h1 { font-size: 30px; margin-bottom: 8px; }
.page h2 { font-size: 22px; margin: 36px 0 12px; padding-top: 12px; border-top: 1px solid var(--border); }
.page h3 { font-size: 17px; margin: 24px 0 8px; }
.page p, .page li { margin: 8px 0; }
.page ul, .page ol { padding-left: 22px; }
.page a { color: var(--primary-dark); }

code {
  font-family: "Cascadia Code", Consolas, monospace;
  font-size: 13.5px;
  background: var(--surface); border: 1px solid var(--border);
  padding: 1px 6px; border-radius: 4px;
}
pre {
  background: var(--code-bg); color: var(--code-text);
  padding: 16px 18px; border-radius: 10px; overflow-x: auto; margin: 12px 0;
}
pre code { background: none; border: none; padding: 0; color: inherit; font-size: 13px; line-height: 1.6; }

table { width: 100%; border-collapse: collapse; margin: 12px 0 24px; font-size: 14px; }
th, td { text-align: left; padding: 8px 12px; border: 1px solid var(--border); }
th { background: var(--surface); font-weight: 600; }

.note {
  margin: 14px 0; padding: 12px 16px;
  border-left: 4px solid var(--primary);
  background: #eff6ff; border-radius: 0 8px 8px 0; font-size: 14px;
}
.note.warn { border-left-color: #f59e0b; background: #fffbeb; }

.footer { text-align: center; color: var(--muted); font-size: 13px; padding: 32px 0 40px; }

@media (max-width: 720px) {
  .nav { display: none; }
  .hero h1 { font-size: 30px; }
}