ul, #myUL {
    list-style-type: none;
}

#myUL {
    margin: 0;
    padding: 0;
}

.caret {
    cursor: pointer;
    -webkit-user-select: none; /* Safari 3.1+ */
    -moz-user-select: none; /* Firefox 2+ */
    -ms-user-select: none; /* IE 10+ */
    user-select: none;
}

    .caret::before {
        content: "\25B6";
        color: darkorange;
        display: inline-block;
        margin-right: 6px;
    }

.caret-down::before {
    -ms-transform: rotate(90deg); /* IE 9 */
    -webkit-transform: rotate(90deg); /* Safari */
    ' transform: rotate(90deg);
}

.nested {
    display: none;
}

.active {
    display: block;
    border: 1px solid orange;
}