body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            background: #f9f9f9;
        }
        header, footer {
            background-color: #007bff;
            color: white;
            padding: 1rem;
            text-align: center;
        }
        main {
            padding: 2rem;
        }
        .card {
            background: white;
            border-radius: 8px;
            padding: 1rem;
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
            max-width: 600px;
            margin: auto;
        }