:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --surface: #f6f7f9;
  --text: #1a1c22;
  --muted: #5b6070;
  --border: #e3e6ec;
  --accent: #1d6fd0;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1017;
    --surface: #161b25;
    --text: #e8ecf3;
    --muted: #a3abbb;
    --border: #2a3240;
    --accent: #78b4ff;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  padding: 0 20px 72px;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 15px;
  line-height: 1.85;
}
.wrap { max-width: 780px; margin: 0 auto; }
.topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 18px;
  padding: 22px 0 18px;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}
.brand { font-weight: 600; color: var(--text); text-decoration: none; margin-right: auto; }
.navlinks { display: flex; flex-wrap: wrap; gap: 14px; }
.lang { display: flex; gap: 8px; }
.topbar a { color: var(--accent); text-decoration: none; }
.topbar a:hover { text-decoration: underline; }
.topbar a[aria-current="page"] { font-weight: 600; text-decoration: underline; text-underline-offset: 3px; }
header { padding: 34px 0 8px; }
h1 { font-size: 28px; line-height: 1.35; margin: 0 0 8px; font-weight: 600; }
.meta { color: var(--muted); font-size: 13px; margin: 0; }
h2 { font-size: 18px; font-weight: 600; margin: 36px 0 10px; padding-top: 4px; }
h3 { font-size: 15px; font-weight: 600; margin: 22px 0 6px; }
p { margin: 10px 0; }
ul, ol { margin: 10px 0; padding-left: 24px; }
li { margin: 5px 0; }
a { color: var(--accent); }
code {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 13px;
  word-break: break-all;
}
.callout {
  background: var(--surface);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 12px 16px;
  margin: 16px 0;
}
table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 14px; }
th, td { border: 1px solid var(--border); padding: 8px 10px; text-align: left; vertical-align: top; }
th { background: var(--surface); font-weight: 600; }
section + section { margin-top: 56px; }
.divider { border: 0; border-top: 1px solid var(--border); margin: 56px 0 0; }
footer {
  margin-top: 48px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 13px;
}
footer a { color: var(--muted); }
@media (max-width: 560px) {
  body { font-size: 14.5px; padding: 0 16px 48px; }
  h1 { font-size: 24px; }
  .brand { width: 100%; }
  table { font-size: 13px; }
  th, td { padding: 6px; }
}