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 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) {
            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');
        })
    };