ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    width: 100%;
    background-color: #f1f1f1;
}

li a {
    display: block;
    color: #000;
    padding: 8px 16px;
    text-decoration: none;
}

    li a.active {
        background-color: #4CAF50;
        color: white;
    }

    li a:hover:not(.active) {
        background-color: #555;
        color: white;
    }