:root { color-scheme: light dark; }
body { font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; max-width: 42rem; margin: 3rem auto; padding: 0 1rem; }
h1 { font-size: 1.8rem; line-height: 1.2; }
h2 { font-size: 1.2rem; margin-top: 2rem; }
nav { margin-bottom: 2rem; font-size: 0.9rem; }
nav a { margin-right: 1rem; }
footer { margin-top: 3rem; font-size: 0.85rem; opacity: 0.7; }