:root {
  color-scheme: light dark;
  --bg: #f6faff;
  --card: #ffffff;
  --ink: #1d3553;
  --muted: #637891;
  --line: #dceafa;
  --blue: #347fdf;
  --blue-soft: #eaf4ff;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
main { max-width: 780px; margin: 0 auto; padding: 38px 20px 72px; }
a { color: var(--blue); }
h1 { margin: 0 0 8px; font-size: clamp(30px, 6vw, 44px); line-height: 1.2; }
h2 { margin: 32px 0 10px; font-size: 21px; }
.subtitle, small { color: var(--muted); }
.hero { padding: 26px; border-radius: 26px; background: linear-gradient(135deg, #66b4ff, #377dd8); color: #fff; box-shadow: 0 18px 45px rgba(52,127,223,.20); }
.hero .subtitle { color: rgba(255,255,255,.82); }
.card { margin-top: 18px; padding: 20px; border: 1px solid var(--line); border-radius: 20px; background: var(--card); }
nav { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 20px; }
nav a { padding: 9px 13px; border-radius: 12px; background: var(--blue-soft); text-decoration: none; font-weight: 600; }
ul { padding-left: 22px; }
footer { margin-top: 36px; color: var(--muted); font-size: 14px; }
@media (prefers-color-scheme: dark) {
  :root { --bg:#0e1b2d; --card:#162740; --ink:#eef6ff; --muted:#afc0d5; --line:#29415f; --blue-soft:#193a63; }
}