:root {
  --fg: #1a1a1a;
  --muted: #555;
  --bg: #ffffff;
  --accent: #0b5cff;
  --line: #e5e7eb;
  --max: 760px;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--fg);
  background: var(--bg);
}
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.site-header {
  border-bottom: 1px solid var(--line);
  padding: 14px 0;
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand {
  font-weight: 700; font-size: 18px; text-decoration: none; color: var(--fg);
}
.primary a {
  margin-left: 16px; text-decoration: none; color: var(--muted); font-size: 15px;
}
.primary a:hover { color: var(--accent); }
main { padding: 32px 0 48px; }
article h1 { font-size: 32px; line-height: 1.25; margin: 0 0 16px; }
article h2 { font-size: 24px; line-height: 1.3; margin: 32px 0 12px; }
article h3 { font-size: 19px; line-height: 1.35; margin: 24px 0 10px; }
article h4 { font-size: 17px; margin: 20px 0 8px; }
article p, article ul, article ol { margin: 0 0 16px; }
article ul, article ol { padding-left: 22px; }
article li { margin: 4px 0; }
article a { color: var(--accent); }
article img { max-width: 100%; height: auto; display: block; margin: 16px auto; }
article blockquote {
  border-left: 3px solid var(--line); padding-left: 14px; color: var(--muted);
  margin: 16px 0;
}
article hr { border: 0; border-top: 1px solid var(--line); margin: 32px 0; }
.page-list { list-style: none; padding: 0; columns: 2; column-gap: 32px; }
.page-list li { margin: 4px 0; break-inside: avoid; }
.page-list a { text-decoration: none; color: var(--accent); }
.page-list a:hover { text-decoration: underline; }
.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 48px;
  padding: 20px 0;
  color: var(--muted);
  font-size: 14px;
}
@media (max-width: 600px) {
  .page-list { columns: 1; }
  article h1 { font-size: 26px; }
  article h2 { font-size: 21px; }
}