body{color:#333;background:#f9f9f9;margin:0;font-family:Arial,sans-serif}header{color:#fff;text-align:center;background:#222;padding:20px}header nav a{color:#fff;margin:0 10px;text-decoration:none}section{max-width:800px;margin:auto;padding:40px}h2{border-bottom:2px solid #ccc;margin-bottom:20px;padding-bottom:10px}