:root {
  --bg: #fafafa;
  --fg: #1d1d1f;
  --muted: #5f6368;
  --card: #ffffff;
  --line: #e5e7eb;
  --accent: #b3261e;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #ececec;
    --muted: #a0a4a8;
    --card: #1c1c1e;
    --line: #2c2c2e;
    --accent: #ff6b5f;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 16px 64px;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 24px;
}
h1 { font-size: 1.7rem; line-height: 1.25; margin: 0 0 4px; }
h2 { font-size: 1.1rem; margin: 28px 0 6px; }
p, li { margin: 8px 0; }
ul { padding-left: 20px; }
.muted { color: var(--muted); font-size: 0.9rem; }
a { color: var(--accent); }
nav { margin-top: 20px; font-size: 0.95rem; }