body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    color: #333;
    background-color: #f4f4f4;
}

header {
    background: #333;
    color: #fff;
    padding: 10px 0;
    text-align: center;
}

nav {
    background: #444;
    color: #fff;
    padding: 10px 0;
    text-align: center;
}

nav a {
    color: #fff;
    margin: 0 10px;
    text-decoration: none;
}

main {
    padding: 20px;
}

footer {
    background: #333;
    color: #fff;
    text-align: center;
    padding: 10px 0;
}

/* Responsive design */
@media screen and (max-width: 600px) {
    nav, main, footer {
        padding-left: 20px;
        padding-right: 20px;
    }
}