.sub-nav {
    background-color: #fff;
    border-bottom: 1px solid #ccc;
    overflow-x: auto;
    overflow-y: hidden;
}

.sub-nav ul {
    margin: 0;
    padding: 0;
    display: flex;
}

.sub-nav li {
    list-style: none;
}

.sub-nav li a {
    display: block;
    padding: 8px 16px;
    text-decoration: none;
    color: inherit;
    border-right: 1px solid #ccc;
    white-space: nowrap; 
}

.sub-nav li a.SELECTED {
    background-color: #f3f3f3;
}