:root {
  --bg: #f7f6f2;
  --surface: #ffffff;
  --text: #1d2327;
  --muted: #5b6770;
  --line: #e2e0d8;
  --accent: #0f7a6c;
  --accent-text: #ffffff;
  --mark: #fff1b8;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14181b;
    --surface: #1c2226;
    --text: #e8ecee;
    --muted: #9aa7ae;
    --line: #2c353a;
    --accent: #3fbfa9;
    --accent-text: #0c1a17;
    --mark: #5a4a10;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
}
a { color: var(--accent); }
mark { background: var(--mark); color: inherit; padding: 0 .2em; }

.top, main, footer { max-width: 760px; margin: 0 auto; padding: 0 16px; }
.top {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: 8px 16px; padding-top: 16px; padding-bottom: 16px; border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 8px; font-weight: 700; color: var(--text); text-decoration: none; }
.top nav { display: flex; flex-wrap: wrap; gap: 4px 16px; font-size: 15px; }
.top nav a { text-decoration: none; }
.top nav a[aria-current="page"] { color: var(--text); font-weight: 600; }

main { padding-top: 24px; padding-bottom: 32px; }
h1 { font-size: 30px; line-height: 1.25; margin: 8px 0 12px; }
h2 { font-size: 21px; margin: 32px 0 8px; }
h3 { font-size: 17px; margin: 20px 0 4px; }
.lead { font-size: 19px; color: var(--muted); margin-top: 0; }
.meta { color: var(--muted); font-size: 14px; }

.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px; margin: 24px 0; padding: 0; list-style: none; }
.facts li { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; }
.facts b { display: block; font-size: 22px; }
.facts span { color: var(--muted); font-size: 14px; }

.card { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; margin: 16px 0; }
.card > :first-child { margin-top: 0; }
.card > :last-child { margin-bottom: 0; }

.button {
  display: inline-block; background: var(--accent); color: var(--accent-text);
  padding: 10px 18px; border-radius: 8px; font-weight: 600; text-decoration: none;
}

ol, ul { padding-left: 1.3em; }
li { margin: 4px 0; }

.table-wrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-size: 15px; margin: 8px 0 16px; }
th, td { text-align: left; vertical-align: top; padding: 8px 10px; border-bottom: 1px solid var(--line); }
th { font-weight: 600; }

footer { border-top: 1px solid var(--line); padding-top: 16px; padding-bottom: 32px; color: var(--muted); font-size: 14px; }
footer p { margin: 4px 0; }