:root {
  --bg: #ffffff;
  --text: #1d1d1f;
  --muted: #6e6e73;
  --link: #0066cc;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #000000; --text: #f5f5f7; --muted: #a1a1a6; --link: #2997ff; }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.55 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
}
main { max-width: 680px; margin: 0 auto; padding: 48px 16px 64px; }
h1 { font-size: 40px; line-height: 1.1; letter-spacing: -0.02em; margin: 8px 0 16px; }
h2 { font-size: 22px; line-height: 1.25; margin: 36px 0 8px; }
p { margin: 0 0 12px; }
.lead { font-size: 21px; line-height: 1.45; color: var(--muted); }
.lang { text-align: right; font-size: 15px; margin: 0; }
.date { margin-top: 36px; font-size: 15px; color: var(--muted); }
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
.center { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; text-align: center; }