:root {
  --bg: #ffffff;
  --fg: #1a1d21;
  --muted: #5b6470;
  --line: #e3e6ea;
  --accent: #2557d6;
  --note-bg: #fff6db;
  --note-fg: #5c4600;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111317;
    --fg: #e8eaed;
    --muted: #9aa3ad;
    --line: #2a2e35;
    --accent: #7ea2ff;
    --note-bg: #3a3000;
    --note-fg: #ffe9a3;
  }
}
* { 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;
}
a { color: var(--accent); }
header, main, footer { max-width: 760px; margin: 0 auto; padding: 0 16px; }
header { display: flex; justify-content: space-between; align-items: center; padding-top: 20px; padding-bottom: 20px; border-bottom: 1px solid var(--line); flex-wrap: wrap; gap: 8px; }
header .brand { font-weight: 700; text-decoration: none; color: var(--fg); font-size: 18px; }
header nav { display: flex; gap: 16px; flex-wrap: wrap; font-size: 14px; }
main { padding-top: 32px; padding-bottom: 48px; }
h1 { font-size: 32px; line-height: 1.2; margin: 0 0 8px; }
h2 { font-size: 20px; margin: 32px 0 8px; }
.meta { color: var(--muted); font-size: 14px; margin: 0 0 24px; }
.note { background: var(--note-bg); color: var(--note-fg); padding: 12px 16px; border-radius: 8px; font-size: 14px; margin: 0 0 24px; }
.hero { padding: 48px 0 16px; }
.hero p { font-size: 18px; color: var(--muted); max-width: 560px; }
.cta { display: inline-block; margin-top: 8px; padding: 10px 18px; border-radius: 8px; background: var(--accent); color: var(--bg); text-decoration: none; font-weight: 600; }
footer { border-top: 1px solid var(--line); padding-top: 20px; padding-bottom: 32px; color: var(--muted); font-size: 14px; display: flex; gap: 16px; flex-wrap: wrap; }