body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #f9f9f9;
}
header, footer {
    background-color: #004d40;
    color: white;
    padding: 1rem;
    text-align: center;
}
nav a {
    margin: 0 10px;
    color: white;
    text-decoration: none;
}
main {
    padding: 2rem;
}