:root { color-scheme: light dark; }
body { margin:0; font:16px/1.5 system-ui,sans-serif; }
main { max-width:40rem; margin:4rem auto; padding:0 1rem; }
h1 { font-size:1.5rem; margin:0 0 1rem; }
footer { margin-top:3rem; opacity:.6; font-size:.875rem; }