JSFiddle - React, Tailwind, and code Playground

HTML

<div id="listContainer">
    <ul id="expList">
        <li style="">
            <label style="margin-top: 50px;border-style: solid;  border-width: 1px; border-color: #7C7C7C; background-color:#E0E0E0">Item A</label>
            <ul>
                <li>itens lista A</li>
            </ul>
        </li>
    </ul>
</div>

CSS

#listContainer {
    margin-top: 15px;
}
#expList li {
    background-color: #dbb;
}
#expList ul, li, label {
    list-style: none;
    margin: 0;
    padding: 0;
    cursor: pointer;
}
#expList p {
    margin: 0;
    display: block;
}
#expList p:hover {
    background-color: #121212;
}
#expList li, label {
    line-height: 140%;
    text-indent: 0px;
    background-position: 1px 8px;
    padding-left: 20px;
    background-repeat: no-repeat;
}
#expList .collapsed {
    /*background-image: url(/MVCxTreeListDemos/DXR.axd?r=1_15-5M3g9);*/
}
#expList .expanded {
    /*background-image: url(/MVCxTreeListDemos/DXR.axd?r=1_15-5M3g9);*/
}
#expList {
    clear: both;
}
.listControl {
    margin-bottom: 15px;
}
.listControl a {
    border: 1px solid #555555;
    color: #555555;
    cursor: pointer;
    height: 1.5em;
    line-height: 1.5em;
    margin-right: 5px;
    padding: 4px 10px;
}
.listControl a:hover {
    background-color: #555555;
    color: #222222;
    font-weight: normal;
}

JavaScript

$(document).ready(function () {
        prepareList()
    });

    function prepareList() {
        $('#expList').find('li:has(ul)')
            .click(function (event) {
            alert(this == event.target ? 'this == event.target' : 'this != event.target')
            if (this == event.target) {

                $(this).toggleClass('expanded');
                $(this).children('ul').toggle('medium');
            }
            return false;
        })
            .addClass('collapsed')
            .children('ul').hide();

        //Create the button funtionality
        $('#expandList')
            .unbind('click')
            .click(function () {
            $('.collapsed').addClass('expanded');
            $('.collapsed').children().show('medium');
        })
        $('#collapseList')
            .unbind('click')
            .click(function () {
            $('.collapsed').removeClass('expanded');
            $('.collapsed').children().hide('medium');
        })
    };