body {
            font-family: Arial, sans-serif;
            line-height: 1.6;
            margin: 0;
            padding: 20px;
            background-color: #f4f4f4;
        }
        .container {
            max-width: 900px;
            margin: 0 auto;
            background-color: white;
            padding: 30px;
            border-radius: 8px;
            box-shadow: 0 0 10px rgba(0,0,0,0.1);
        }
        h1 {
            color: #333;
            border-bottom: 3px solid #007bff;
            padding-bottom: 10px;
        }
        .nav {
            margin: 20px 0;
        }
        .nav li {
            display: inline;
        }
        .nav a {
            margin-right: 15px;
            text-decoration: none;
            color: #007bff;
        }
        .nav a:hover {
            text-decoration: underline;
        }
        .sections {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin-top: 30px;
        }
        .card {
            background-color: #f9f9f9;
            padding: 15px;
            border-left: 4px solid #007bff;
            border-radius: 4px;
        }