body {
        font-family: Arial, sans-serif;
        line-height: 1.6;
        margin: 0;
        padding: 0;
        background-color: #f4f4f4;
    }

    header {
        background: #333;
        color: #fff;
        padding: 1rem 0;
        text-align: center;
    }

    nav ul {
        background: #444;
        list-style: none;
        padding: 0;
        text-align: center;
        margin: 0;
    }

    nav ul li {
        display: inline;
    }

    nav ul li a {
        color: #fff;
        padding: 0.5rem 1rem;
        display: inline-block;
        text-decoration: none;
    }

    nav ul li a:hover {
        background: #555;
    }

    section {
        padding: 1rem;
        margin: 1rem auto;
        max-width: 800px;
        background: #fff;
        border-radius: 5px;
        box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    }