/* Remove default bullets */
ul, .treeview {
    list-style-type: none;
}

/* Remove margins and padding from the parent ul */
.treeview {
    margin: 0;
    padding: 0;
}

/* Hide the nested list */
.nested {
    display: none;
}

/* Show the nested list when the user clicks on the caret/arrow (with JavaScript) */
.active {
    display: block;
}