:root { --brand: #1f3a5f; --text: #1b2430; --muted: #5d6775; --bg: #f5f6f8; --border: #d9dde3; --link: #2f6db5; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) { --brand: #9cc0ea; --text: #e8ecf2; --muted: #a8b2c0; --bg: #121820; --border: #2a3442; --link: #8fb8ee; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.6 system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif; }
header, main, footer { max-width: 760px; margin: 0 auto; padding: 0 16px; }
header { padding-top: 32px; display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 8px; }
header a.logo { font-weight: 800; font-size: 22px; letter-spacing: 0.06em; color: var(--brand); text-decoration: none; }
nav a { margin-left: 16px; color: var(--muted); text-decoration: none; }
nav a:hover { color: var(--text); }
h1 { font-size: 32px; line-height: 1.2; margin: 40px 0 8px; }
h2 { font-size: 20px; margin: 32px 0 8px; }
a { color: var(--link); }
.lead { font-size: 19px; color: var(--muted); }
footer { margin-top: 56px; padding-top: 16px; padding-bottom: 32px; border-top: 1px solid var(--border); color: var(--muted); font-size: 14px; }
ul { padding-left: 22px; }