:root{color-scheme:light dark;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}body{margin:0;background:#fafafa;color:#222}@media(prefers-color-scheme:dark){body{background:#111;color:#ddd}}main{max-width:640px;margin:8vh auto;padding:0 1.25rem;line-height:1.6}h1{font-weight:600;letter-spacing:-.02em}a{color:#0a66c2}footer{margin-top:3rem;font-size:.85rem;opacity:.7}