/* Subcategories shown by default */
.has-collapsible-children > ul {
    display: none;
}

/* Expanded state shows them */
.has-collapsible-children.expanded > ul {
    display: block;
}

.category-toggle-btn {
    cursor: pointer;
    display: inline-block;
    width: 20px;
    height: 20px;
    text-align: center;
    line-height: 20px;
    margin-right: 5px;
    font-weight: bold;
    user-select: none;
    border: 1px solid #ccc;
    border-radius: 3px;
}