nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #002855 /* #333 */;
}

nav ul li {
    float: left;
}

nav ul li a {
    display: block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}

nav ul li a:hover:not(.active) {
    background-color: #111;
}

.active {
    background-color: #daaa00 /* #4CAF50 */;
    color: #002855;
}