*,*::before,*::after{box-sizing:border-box}
body{font-family:system-ui,-apple-system,sans-serif;line-height:1.6;margin:0;padding:2rem;background:#f8fafc;color:#0f172a}
main{max-width:640px;margin:0 auto}
h1{font-size:2rem;margin-bottom:0.5rem}