:root { color-scheme: light dark; }
body { font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Helvetica Neue", sans-serif; max-width: 42rem; margin: 0 auto; padding: 2rem 1.25rem 4rem; }
header nav a { margin-right: 1rem; }
h1 { line-height: 1.2; }
footer { margin-top: 3rem; font-size: 0.9rem; opacity: 0.8; }