:root { --bg: #f5f5f7; --card: #fff; --text: #1d1d1f; --muted: #6e6e73; --accent: #0071e3; color-scheme: light dark; }
@media (prefers-color-scheme: dark) { :root { --bg: #000; --card: #1c1c1e; --text: #f5f5f7; --muted: #a1a1a6; --accent: #2997ff; } }
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font: 17px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", system-ui, sans-serif; }
main { max-width: 720px; margin: 0 auto; padding: 48px 16px 64px; }
article { background: var(--card); border-radius: 28px; padding: 32px 28px; }
h1 { font-size: 34px; line-height: 1.15; margin: 0 0 4px; }
h2 { font-size: 20px; margin: 28px 0 6px; }
p, li { color: var(--text); }
.muted { color: var(--muted); font-size: 15px; }
a { color: var(--accent); text-decoration: none; }
nav { display: flex; gap: 20px; margin-bottom: 24px; font-weight: 600; }