:root {
  --bg: #f7f7f5;
  --surface: #ffffff;
  --ink: #1c2128;
  --muted: #5f6873;
  --line: #dfe3e8;
  --accent: #1f5f8b;
  --accent-soft: #e6eef5;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101418;
    --surface: #171c22;
    --ink: #e7ebef;
    --muted: #9aa5b1;
    --line: #2a323b;
    --accent: #8fbce6;
    --accent-soft: #1c2a38;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); }
.wrap { max-width: 72ch; margin: 0 auto; padding: 40px 22px 80px; }
header.top {
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  padding-bottom: 18px; border-bottom: 1px solid var(--line); margin-bottom: 28px;
  font-size: .92rem; color: var(--muted);
}
header.top .brand { font-weight: 700; color: var(--ink); text-decoration: none; letter-spacing: .01em; }
header.top nav a { margin-left: 14px; text-decoration: none; }
header.top nav a[aria-current] { color: var(--muted); }
h1 { font-size: 2rem; line-height: 1.2; margin: 0 0 6px; letter-spacing: -.01em; }
.effective { color: var(--muted); font-size: .92rem; margin: 0 0 28px; }
h2 { font-size: 1.25rem; margin: 36px 0 10px; line-height: 1.3; }
h3 { font-size: 1.02rem; margin: 22px 0 6px; }
p, li { margin: 0 0 10px; }
ul { padding-left: 1.3em; margin: 0 0 12px; }
table { border-collapse: collapse; width: 100%; margin: 12px 0 18px; font-size: .95rem; }
th, td { text-align: left; vertical-align: top; padding: 8px 10px; border-bottom: 1px solid var(--line); }
th { color: var(--muted); font-weight: 600; font-size: .82rem; letter-spacing: .04em; text-transform: uppercase; }
.table-wrap { overflow-x: auto; }
.callout {
  background: var(--accent-soft); border-left: 3px solid var(--accent);
  padding: 12px 16px; border-radius: 6px; margin: 16px 0;
}
.callout p:last-child { margin-bottom: 0; }
footer.bottom {
  margin-top: 48px; padding-top: 16px; border-top: 1px solid var(--line);
  color: var(--muted); font-size: .88rem;
}
footer.bottom a { margin-right: 14px; }
.toc { padding-left: 1.2em; margin-bottom: 24px; font-size: .95rem; }
.toc li { margin-bottom: 4px; }
.index-list { list-style: none; padding: 0; }
.index-list li {
  background: var(--surface); border: 1px solid var(--line); border-radius: 8px;
  padding: 14px 16px; margin-bottom: 10px;
}
.index-list a { font-weight: 600; text-decoration: none; }
.index-list span { display: block; color: var(--muted); font-size: .9rem; margin-top: 2px; }