:root {
  color-scheme: light;
  --bg: #f7f8fa;
  --text: #1d232f;
  --muted: #5f6b7a;
  --line: #dfe4ea;
  --panel: #ffffff;
  --accent: #176b87;
  --accent-2: #c15f3c;
}
* { box-sizing: border-box; }
html { min-height: 100%; }
body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  letter-spacing: 0;
}
a { color: inherit; text-decoration: none; }
.site-header {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--line);
}
.brand { display: inline-flex; align-items: center; gap: 12px; font-weight: 700; font-size: 18px; }
.logo {
  width: 34px;
  height: 34px;
  display: inline-grid;
  place-items: center;
  border-radius: 6px;
  background: var(--text);
  color: white;
  font-size: 18px;
}
.nav { display: flex; gap: 8px; flex-wrap: wrap; justify-content: flex-end; }
.nav a { padding: 8px 10px; color: var(--muted); font-size: 14px; }
.nav a:hover { color: var(--text); }
.main { width: min(1080px, calc(100% - 32px)); margin: 0 auto; flex: 1; }
.hero { padding: clamp(72px, 14vh, 150px) 0 56px; max-width: 760px; }
.eyebrow { margin: 0 0 18px; color: var(--accent); font-size: 14px; font-weight: 700; }
h1 { margin: 0; font-size: clamp(42px, 8vw, 82px); line-height: 1.05; letter-spacing: 0; }
.intro { margin: 24px 0 0; color: var(--muted); font-size: clamp(18px, 3vw, 24px); line-height: 1.7; max-width: 680px; }
.notes, .page {
  border-top: 1px solid var(--line);
  padding: 32px 0 72px;
}
.notes article, .page { max-width: 720px; }
h2 { margin: 0 0 12px; font-size: 22px; }
p { line-height: 1.8; }
.notes p, .page p { color: var(--muted); margin: 0; }
.footer {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
  padding: 24px 0 32px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
}
.footer a { color: var(--muted); }
.footer a:hover { color: var(--text); }
@media (max-width: 640px) {
  .site-header { align-items: flex-start; flex-direction: column; padding: 18px 0; gap: 14px; }
  .nav { justify-content: flex-start; }
  .hero { padding-top: 56px; }
}