* {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

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

.caret {
    cursor: pointer;
    user-select: none;
}

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

.caret-down::before {
    transform: rotate(90deg);
}

.nested {
    margin-left: 20px;
    display: none;
}

.active {
  margin-left: 20px;
  display: block;
}