:root { color-scheme: light dark; }
body { font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; max-width: 40rem; margin: 0 auto; padding: 2rem 1rem; }
nav { margin-bottom: 2rem; }
nav a { margin-right: 1rem; }
footer { margin-top: 3rem; font-size: 0.9em; opacity: 0.7; }