:root { --bg: #ffffff; --fg: #1f2937; --muted: #6b7280; --line: #e5e7eb; --accent: #2563eb; }
@media (prefers-color-scheme: dark) { :root { --bg: #111827; --fg: #e5e7eb; --muted: #9ca3af; --line: #374151; --accent: #60a5fa; } }
* { 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; }
main { max-width: 760px; margin: 0 auto; padding: 40px 16px 64px; }
header { display: flex; justify-content: space-between; align-items: center; gap: 16px; border-bottom: 1px solid var(--line); padding-bottom: 16px; margin-bottom: 24px; flex-wrap: wrap; }
.brand { font-weight: 700; font-size: 20px; color: var(--fg); text-decoration: none; }
nav a, a { color: var(--accent); }
nav a { margin-left: 16px; text-decoration: none; }
h1 { font-size: 28px; line-height: 1.25; }
h2 { font-size: 20px; margin-top: 32px; }
h3 { font-size: 17px; margin-top: 24px; }
.muted { color: var(--muted); font-size: 14px; }
.button { display: inline-block; background: var(--accent); color: var(--bg); padding: 10px 18px; border-radius: 8px; text-decoration: none; font-weight: 600; }
hr { border: 0; border-top: 1px solid var(--line); margin: 48px 0; }
footer { border-top: 1px solid var(--line); margin-top: 48px; padding-top: 16px; }