:root {
  --bg: #f3f4f2;
  --surface: #ffffff;
  --ink: #191b19;
  --muted: #687068;
  --rule: #cfd4ce;
  --accent: #216e4e;
  --accent-soft: #e1eee7;
  --max: 1040px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--bg); font-family: Inter, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif; line-height: 1.72; -webkit-font-smoothing: antialiased; }
a { color: inherit; }
.container { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }
.site-nav { position: sticky; top: 0; z-index: 10; border-bottom: 1px solid color-mix(in srgb, var(--rule) 78%, transparent); background: color-mix(in srgb, var(--bg) 92%, transparent); backdrop-filter: blur(14px); }
.nav-inner { min-height: 66px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { font-weight: 750; text-decoration: none; letter-spacing: -.02em; }
.nav-links { display: flex; gap: 18px; align-items: center; font-size: 14px; color: var(--muted); }
.nav-links a { text-decoration: none; }
.nav-links a:hover { color: var(--accent); }
.hero { padding: 92px 0 72px; border-bottom: 1px solid var(--rule); }
.eyebrow { margin: 0 0 18px; color: var(--accent); font-size: 13px; font-weight: 750; letter-spacing: .1em; text-transform: uppercase; }
h1, h2, h3 { line-height: 1.18; letter-spacing: -.035em; }
h1 { max-width: 820px; margin: 0; font-size: clamp(42px, 7vw, 72px); }
.lead { max-width: 760px; margin: 26px 0 0; color: #3c443d; font-size: clamp(18px, 2.5vw, 22px); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.button { display: inline-flex; align-items: center; min-height: 44px; padding: 0 18px; border: 1px solid var(--ink); border-radius: 6px; text-decoration: none; font-weight: 700; }
.button.primary { border-color: var(--accent); color: #fff; background: var(--accent); }
.button:hover { transform: translateY(-1px); }
.article { padding: 64px 0 88px; }
.toc { margin-bottom: 48px; padding: 20px 22px; border: 1px solid var(--rule); border-radius: 10px; background: var(--surface); }
.toc strong { display: block; margin-bottom: 8px; }
.toc a { margin-right: 16px; color: var(--accent); text-decoration: none; }
.article section { scroll-margin-top: 90px; margin-top: 58px; }
.article h2 { max-width: 760px; margin: 0 0 18px; font-size: clamp(29px, 4vw, 42px); }
.article h3 { margin: 0 0 10px; font-size: 21px; }
.article p, .article li { max-width: 790px; color: #3c443d; }
.article p { margin: 0 0 18px; }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-top: 24px; }
.card { padding: 24px; border: 1px solid var(--rule); border-radius: 10px; background: var(--surface); }
.card p { margin-bottom: 0; }
.callout { margin: 28px 0; padding: 24px; border-left: 4px solid var(--accent); background: var(--accent-soft); }
.callout strong { display: block; margin-bottom: 6px; }
.checklist { padding-left: 1.2em; }
.checklist li { margin: 9px 0; }
.table-wrap { overflow-x: auto; margin: 24px 0; border: 1px solid var(--rule); border-radius: 10px; }
table { width: 100%; min-width: 680px; border-collapse: collapse; background: var(--surface); }
th, td { padding: 15px 16px; border-bottom: 1px solid var(--rule); text-align: left; vertical-align: top; }
th { color: var(--muted); font-size: 13px; }
tr:last-child td { border-bottom: 0; }
.faq details { max-width: 820px; padding: 18px 0; border-bottom: 1px solid var(--rule); }
.faq summary { cursor: pointer; font-weight: 750; }
.faq details p { margin-top: 12px; }
.related { padding: 28px; border-radius: 12px; color: #fff; background: #1a2a20; }
.related a { color: #fff; }
.site-footer { padding: 32px 0; border-top: 1px solid var(--rule); color: var(--muted); font-size: 14px; }
.footer-inner { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.footer-links { display: flex; flex-wrap: wrap; gap: 16px; }
.footer-links a { text-decoration: none; }
@media (max-width: 720px) {
  .container { width: min(100% - 28px, var(--max)); }
  .nav-inner { min-height: 58px; }
  .nav-links a:not(:last-child) { display: none; }
  .hero { padding: 66px 0 52px; }
  h1 { font-size: 42px; }
  .article { padding-top: 44px; }
  .grid { grid-template-columns: 1fr; }
  .toc a { display: block; margin: 7px 0; }
}