body{font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;line-height:1.5;margin:0}
header,main,footer{max-width:920px;margin:auto;padding:24px}
h1{font-size:2rem;margin:.5rem 0}
nav a{margin-right:12px}
.cta{display:inline-block;padding:12px 16px;border:1px solid #000;text-decoration:none}
ul{padding-left:18px}
details{margin:8px 0}
form input{padding:10px;margin-right:8px}
form button{padding:10px 14px}