:root{color-scheme:light dark;--fg:#111;--muted:#555;--bg:#fff}*{box-sizing:border-box}body,html{margin:0;padding:0}body{font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--fg);background:var(--bg);line-height:1.6}main{max-width:42rem;margin:0 auto;padding:4rem 1.5rem}h1{font-size:2rem;line-height:1.2}footer{margin-top:3rem;color:var(--muted);font-size:.9rem}footer nav{display:flex;gap:1rem}