:root {
  --ink: #172026;
  --muted: #5d6870;
  --line: #d8dee2;
  --surface: #ffffff;
  --surface-soft: #f5f7f6;
  --brand: #087f5b;
  --brand-dark: #056047;
  --accent: #b45309;
  --danger: #b42318;
  --max-width: 920px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--surface);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.75;
}

a { color: var(--brand-dark); text-underline-offset: 3px; }
a:hover { color: var(--accent); }

.site-header {
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav-shell,
.footer-shell,
.page-shell {
  width: min(calc(100% - 32px), var(--max-width));
  margin: 0 auto;
}

.nav-shell {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 750;
  text-decoration: none;
  white-space: nowrap;
}

.brand-mark {
  display: inline-grid;
  width: 34px;
  height: 34px;
  place-items: center;
  color: #fff;
  background: var(--brand);
  border-radius: 6px;
  font-size: 14px;
}

.site-nav { display: flex; align-items: center; gap: 18px; font-size: 15px; }
.site-nav a { color: var(--ink); text-decoration: none; }
.site-nav .nav-cta { color: #fff; background: var(--brand); padding: 8px 12px; border-radius: 6px; }
.site-nav .nav-cta:hover { background: var(--brand-dark); }

.page-shell { padding: 34px 0 72px; }
.content { min-width: 0; }
.content > :first-child { margin-top: 0; }

h1, h2, h3 { line-height: 1.3; letter-spacing: 0; color: #10181d; }
h1 { font-size: 2.15rem; margin: 0 0 18px; }
h2 { font-size: 1.55rem; margin: 48px 0 14px; padding-top: 6px; border-top: 1px solid var(--line); }
h3 { font-size: 1.18rem; margin: 30px 0 8px; }

p, ul, ol, table, blockquote { margin: 0 0 20px; }
li + li { margin-top: 7px; }

blockquote {
  border-left: 4px solid var(--brand);
  background: var(--surface-soft);
  padding: 14px 18px;
  color: #304047;
}

table { width: 100%; border-collapse: collapse; display: block; overflow-x: auto; }
th, td { min-width: 140px; border: 1px solid var(--line); padding: 11px 12px; text-align: left; vertical-align: top; }
th { background: var(--surface-soft); }

code { background: #eef1f2; border-radius: 4px; padding: 2px 5px; font-size: 0.92em; }

.lead { font-size: 1.08rem; color: #34434b; }
.meta { color: var(--muted); font-size: 0.92rem; }
.notice { border-left: 4px solid var(--accent); padding: 12px 16px; background: #fff8ed; }
.warning { border-left-color: var(--danger); background: #fff5f4; }

.primary-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 9px 15px;
  color: #fff;
  background: var(--brand);
  border-radius: 6px;
  font-weight: 700;
  text-decoration: none;
}
.primary-link:hover { color: #fff; background: var(--brand-dark); }

.guide-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; margin: 24px 0; }
.guide-card { border: 1px solid var(--line); border-radius: 6px; padding: 18px; background: var(--surface); }
.guide-card h3 { margin-top: 0; }
.guide-card p:last-child { margin-bottom: 0; }

.breadcrumbs { display: flex; flex-wrap: wrap; gap: 8px; color: var(--muted); font-size: 0.9rem; margin-bottom: 22px; }
.breadcrumbs a { color: var(--muted); }

.faq-section details { border-top: 1px solid var(--line); padding: 14px 0; }
.faq-section details:last-child { border-bottom: 1px solid var(--line); }
.faq-section summary { cursor: pointer; font-weight: 700; }
.faq-section details p { margin: 10px 0 0; color: #34434b; }

.site-footer { border-top: 1px solid var(--line); background: var(--surface-soft); }
.footer-shell { padding: 30px 0; color: var(--muted); font-size: 0.92rem; }
.footer-shell p { margin-bottom: 8px; }

@media (max-width: 760px) {
  body { font-size: 16px; }
  .nav-shell { align-items: flex-start; flex-direction: column; padding: 12px 0; gap: 10px; }
  .site-header { position: static; }
  .site-nav { width: 100%; flex-wrap: wrap; gap: 8px 12px; padding-bottom: 2px; }
  .site-nav a { white-space: nowrap; }
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.35rem; }
  .guide-grid { grid-template-columns: 1fr; }
  th, td { min-width: 126px; }
}