/* Base styles */
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #4CAF50;
    color: white;
    padding: 1em;
    text-align: center;
}

main {
    padding: 1em;
}

/* Mobile styles */
@media (max-width: 600px) {
    header {
        font-size: 1.5em;
    }
    main {
        padding: 0.5em;
    }
}