:root { color-scheme: light dark; font-family: system-ui, sans-serif; }
body { margin: 0; line-height: 1.6; }
main { max-width: 42rem; margin: 12vh auto; padding: 1.5rem; }
h1 { line-height: 1.2; }
:focus-visible { outline: 3px solid currentColor; outline-offset: 4px; }