body{font-family:Arial,sans-serif;margin:0;padding:0;background-color:#f9f9f9}h1{text-align:center;margin-top:20px}p{text-align:center;font-size:16px;margin:10px auto}.top-nav{background-color:#333;overflow:hidden}.top-nav ul{margin:0;padding:0;list-style:none;display:flex;justify-content:center}.top-nav li{margin:0;padding:10px}.top-nav a{text-decoration:none;color:#fff;padding:10px 20px;display:block}.top-nav a:hover{background-color:#575757}