body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
}

header, nav, main, footer {
    margin: 0 auto;
    max-width: 800px;
    padding: 20px;
}

header {
    background: #f8f9fa;
    text-align: center;
    border-bottom: 1px solid #ddd;
}

nav ul {
    list-style: none;
    padding: 0;
    text-align: center;
}

nav ul li {
    display: inline;
    margin: 0 10px;
}

nav ul li a {
    text-decoration: none;
    color: #007bff;
}

main {
    margin-top: 20px;
}

main section {
    margin-bottom: 40px;
}

footer {
    background: #f8f9fa;
    text-align: center;
    border-top: 1px solid #ddd;
    margin-top: 20px;
}