:root {
  color-scheme: light;
  --fg: #1a1a1a;
  --muted: #666;
  --line: #e8e8e8;
  --bg: #f7f8fa;
  --card: #fff;
  --link: #1677ff;
  --tip: #f5f7fb;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.75;
  font-size: 15px;
  -webkit-text-size-adjust: 100%;
}
.wrap { max-width: 720px; margin: 0 auto; padding: 24px 16px 48px; }
.card {
  background: var(--card);
  border-radius: 12px;
  padding: 28px 22px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}
h1 {
  margin: 0 0 8px;
  font-size: 22px;
  font-weight: 600;
  text-align: center;
  line-height: 1.4;
}
.meta {
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 24px;
}
h2 {
  margin: 28px 0 12px;
  font-size: 17px;
  font-weight: 600;
  padding-top: 8px;
  border-top: 1px solid var(--line);
  scroll-margin-top: 12px;
}
h2:first-of-type { border-top: none; padding-top: 0; }
h3 { margin: 18px 0 8px; font-size: 15px; font-weight: 600; }
p, li { margin: 0 0 10px; }
ul, ol { padding-left: 1.3em; margin: 0 0 12px; }
strong { font-weight: 600; }
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
.note, .toc {
  background: var(--tip);
  border-radius: 8px;
  padding: 12px 14px;
  color: #333;
  font-size: 14px;
  margin: 16px 0;
}
.toc { margin: 0 0 8px; }
.toc ol { margin: 0; padding-left: 1.4em; }
.toc li { margin: 0 0 6px; }
.warn {
  background: #fff7f0;
  border-left: 3px solid #fa8c16;
  border-radius: 0 8px 8px 0;
  padding: 12px 14px;
  font-size: 14px;
  margin: 16px 0;
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin: 12px 0 16px;
}
th, td {
  border: 1px solid var(--line);
  padding: 10px 8px;
  text-align: left;
  vertical-align: top;
}
th { background: #f5f7fb; font-weight: 600; }
.table-scroll, .scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }
footer {
  margin-top: 28px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}