body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
header {
    background: #333;
    color: #fff;
    padding: 10px;
}
nav ul {
    list-style: none;
    padding: 0;
}
nav ul li {
    display: inline;
    margin-right: 15px;
}
nav a {
    color: #fff;
    text-decoration: none;
}