:root {
  color: #172033;
  background: #f8fafc;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}

* { box-sizing: border-box; }

body { margin: 0; }

a { color: #2563eb; text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  border-bottom: 1px solid #e2e8f0;
  background: rgba(255, 255, 255, .95);
}

.header-inner,
.page {
  width: min(100% - 32px, 960px);
  margin: 0 auto;
}

.header-inner {
  display: flex;
  min-height: 64px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand { color: #0f172a; font-weight: 800; font-size: 1.2rem; }
.site-nav { display: flex; flex-wrap: wrap; gap: 16px; font-size: .94rem; }

.page { padding: 56px 0 72px; }
.eyebrow { margin: 0 0 10px; color: #2563eb; font-size: .9rem; font-weight: 700; }
h1 { margin: 0; max-width: 780px; color: #0f172a; font-size: clamp(2rem, 5vw, 3.25rem); line-height: 1.2; }
.lead { max-width: 760px; margin: 20px 0 0; color: #475569; font-size: 1.12rem; }

.content-grid { display: grid; gap: 20px; margin-top: 40px; }
.card {
  padding: 28px;
  border: 1px solid #e2e8f0;
  border-radius: 16px;
  background: #fff;
  box-shadow: 0 8px 28px rgba(15, 23, 42, .05);
}
.card h2 { margin: 0; color: #0f172a; font-size: 1.35rem; }
.card p { margin: 12px 0 0; color: #475569; }
.card ul { margin: 12px 0 0; padding-left: 1.25rem; color: #475569; }
code { padding: .15em .35em; border-radius: 4px; background: #eff6ff; color: #1d4ed8; }
.meta { margin-top: 36px; color: #64748b; font-size: .9rem; }

@media (max-width: 640px) {
  .header-inner { padding: 12px 0; align-items: flex-start; flex-direction: column; }
  .page { padding-top: 40px; }
  .card { padding: 22px; }
}