body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f9;
    color: #333;
}
header {
    background-color: #004d99;
    color: white;
    padding: 20px;
    text-align: center;
}
header h1 {
    margin: 0;
    font-size: 2.5em;
}
nav {
    background-color: #333;
    overflow: hidden;
}
nav a {
    float: left;
    display: block;
    color: white;
    text-align: center;
    padding: 14px 20px;
    text-decoration: none;
}
nav a:hover {
    background-color: #ddd;
    color: black;
}
main, .container {
    padding: 20px;
}
footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 10px;
    margin-top: 40px;
}
@media (max-width: 768px) {
    nav a {
        float: none;
        width: 100%;
    }
}