:root {
  --bg: #ffffff;
  --fg: #1c1c1e;
  --muted: #6b6b70;
  --accent: #d32f2f;
  --card: #f6f6f7;
  --line: #e4e4e7;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #121214; --fg: #ececee; --muted: #a0a0a6; --accent: #ef5350; --card: #1e1e22; --line: #2c2c31; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.6 -apple-system, "Segoe UI", Roboto, Arial, sans-serif; }
a { color: var(--accent); }
.top { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px 16px; border-bottom: 1px solid var(--line); max-width: 960px; margin: 0 auto; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--fg); text-decoration: none; font-weight: 600; }
select { background: var(--card); color: var(--fg); border: 1px solid var(--line); border-radius: 8px; padding: 6px 8px; font: inherit; }
main { max-width: 960px; margin: 0 auto; padding: 0 16px 32px; }
.hero { text-align: center; padding: 48px 0 24px; }
.hero h1 { margin: 12px 0 4px; font-size: 2.2rem; }
.lead { font-size: 1.25rem; margin: 0 0 8px; }
.muted { color: var(--muted); }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; margin: 24px 0; }
.feature, .card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 18px; }
.feature h3, .card h3 { margin: 0 0 6px; font-size: 1.05rem; }
.feature p, .card p { margin: 0; color: var(--muted); }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; margin: 8px 0 24px; }
.card.accent { border-color: var(--accent); }
.doc { max-width: 760px; margin: 0 auto; }
.doc h1 { margin-top: 32px; }
.doc h2 { font-size: 1.15rem; margin: 28px 0 6px; }
footer { text-align: center; color: var(--muted); padding: 24px 16px 40px; border-top: 1px solid var(--line); }