:root {
  --primary: #4F46E5;
  --bg: #F8FAFC;
  --surface: #FFFFFF;
  --border: #E2E8F0;
  --text: #0F172A;
  --muted: #64748B;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0B1120;
    --surface: #111827;
    --border: #1F2937;
    --text: #F1F5F9;
    --muted: #94A3B8;
    --primary: #818CF8;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  font-size: 16px;
}
a { color: var(--primary); }
header, main, footer { max-width: 720px; margin: 0 auto; padding: 0 16px; }
header { padding-top: 32px; padding-bottom: 8px; }
.brand { font-size: 24px; font-weight: 700; color: var(--primary); text-decoration: none; letter-spacing: -0.02em; }
main { padding-top: 24px; padding-bottom: 48px; }
h1 { font-size: 32px; line-height: 1.2; margin: 0 0 12px; letter-spacing: -0.02em; }
h2 { font-size: 20px; margin: 32px 0 8px; }
p, li { color: var(--text); }
.lede { font-size: 20px; color: var(--muted); margin: 0 0 24px; }
.muted { color: var(--muted); font-size: 14px; }
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px;
  margin: 16px 0;
}
footer {
  padding-top: 16px;
  padding-bottom: 40px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
}
footer a { margin-right: 16px; }