body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: #f5f5f5;
    color: #333;
}
header {
    background: #2c3e50;
    color: white;
    padding: 1em;
    text-align: center;
}
nav a {
    color: white;
    margin: 0 1em;
    text-decoration: none;
}
main {
    padding: 2em;
}
footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 1em;
    position: fixed;
    bottom: 0;
    width: 100%;
}
@media (max-width: 600px) {
    nav a {
        display: block;
        margin: 0.5em 0;
    }
}