body{font-family:Arial,sans-serif;line-height:1.6;color:#333;margin:0;padding:0;}header{background-color:#f4f4f9;padding:20px;text-align:center;border-bottom:1px solid #ddd;}header h1{margin:0;font-size:2rem;color:#333;}header p{color:#555;margin:5px 0 10px;}nav ul{list-style:none;padding:0;margin:0;display:flex;justify-content:center;gap:15px;}nav ul li{display:inline;}nav ul li a{text-decoration:none;color:#0077cc;font-weight:bold;}nav ul li a.active,nav ul li a:hover{text-decoration:underline;color:#0056a8;}main{padding:20px;max-width:800px;margin:auto;}