body{font-family:Arial,sans-serif;margin:0;padding:0}header{background-color:#f8f8f8;padding:20px;text-align:center}nav{margin-top:10px}nav a{margin:0 10px;text-decoration:none;color:#333}main{padding:20px}footer{background-color:#f8f8f8;padding:10px;text-align:center;margin-top:20px}