JSFiddle - React, Tailwind, and code Playground

HTML

<nav class="left-menu">
    <ul class="list-items">
        <li><a href="http://wp.pl">test</a></li>
        <li><a href="http://wp.pl">test</a></li>
        <li>
            <a href="#">test</a>
            <ul>
                <li><a href="http://wp.pl">test</a></li>
                <li><a href="http://wp.pl">test</a></li>
            </ul>
        </li>
    </ul>
</nav>

CSS

li {list-style: none;}
.left-menu li a{display: block; text-align: left; padding: 10px 10px 10px 20px; border-top: 1px solid #dfdfdf;
               font-size: 14px;
               
    background: #ffffff; /* Old browsers */
    background: -moz-linear-gradient(top, #ffffff 0%, #ededed 100%); /* FF3.6+ */
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#ffffff), color-stop(100%,#ededed)); /* Chrome,Safari4+ */
    background: -webkit-linear-gradient(top, #ffffff 0%,#ededed 100%); /* Chrome10+,Safari5.1+ */
    background: -o-linear-gradient(top, #ffffff 0%,#ededed 100%); /* Opera 11.10+ */
    background: -ms-linear-gradient(top, #ffffff 0%,#ededed 100%); /* IE10+ */
    background: linear-gradient(to bottom, #ffffff 0%,#ededed 100%); /* W3C */
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#ffffff', endColorstr='#ededed',GradientType=0 ); /* IE6-9 */
}
.left-menu li a:hover {
            background: rgb(130,203,9)!important;
        background: -moz-linear-gradient(top, rgba(130,203,9,1) 0%, rgba(100,156,9,1) 100%)!important;
        background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(130,203,9,1)), color-stop(100%,rgba(100,156,9,1)))!important;
        background: -webkit-linear-gradient(top, rgba(130,203,9,1) 0%,rgba(100,156,9,1) 100%)!important;
        background: -o-linear-gradient(top, rgba(130,203,9,1) 0%,rgba(100,156,9,1) 100%)!important;
        background: -ms-linear-gradient(top, rgba(130,203,9,1) 0%,rgba(100,156,9,1) 100%)!important;
        background: linear-gradient(to bottom, rgba(130,203,9,1) 0%,rgba(100,156,9,1) 100%)!important;
        filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#82cb09', endColorstr='#649c09',GradientType=0 )!important; 
	color: #FFFFFF!important;
}
.left-menu li a:before {
    content: '\00BB';
    margin-right: 8px;
    color: #e97f07!important;
}

.left-menu  ul ul {visibility: hidden;
                   height: 0;
    ...

JavaScript

$(function(){
    $('.list-items > li').click(function(e) {
        var href = $('a', this).attr('href');
        if( href === '#') {
            e.preventDefault();
            $('ul', this).toggleClass('show');
        }
       
    });   
});