JSFiddle - React, Tailwind, and code Playground

HTML

<div class="tab_container">
    <div id="test1-header" class="accordion_headings header_highlight" >Home<span class="arrow"></span></div>
  <div id="test2-header" class="accordion_headings" >About<span class="arrow"></span></div>
  <div id="test3-header" class="accordion_headings" >Work<span class="arrow"></span></div>
  <div id="test4-header" class="accordion_headings" >Social<span class="arrow"></span></div>
  <div id="test5-header" class="accordion_headings" >Contact<span class="arrow"></span></div>
</div>

CSS

<style type="text/css">
* {
    margin:0;
    padding:0;
    list-style:none;
}
body {
    font-family: Arial, Helvetica, sans-serif;
    font-size: 11px;
    margin:10px;
}

#main-content2{
    border:1px solid #000;
    padding:5px;
    width:590px;
    position:absolute;
    left:50%;
    top:40%;
    margin-left:-325px;
    z-index:1;
    margin-top:-80px;
    -moz-box-shadow: 5px 5px 5px #aeaeae;
    -webkit-box-shadow: 5px 5px 5px #aeaeae;
    box-shadow: 5px 5px 5px #aeaeae;

}


#main-content{
    border:1px solid #000;
    width:560px;
    height:230px;
    margin:10px auto;
}

.accordion_headings{
    width:100%;
    padding:5px;
    background:#fff;
    color:#000;
    cursor:pointer;
    font-weight:bold;
    border-bottom:1px solid black;
}

/*
.accordion_headings:hover{
    background:#00CCFF;
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-bottom: 5px solid red;
}
*/
.accordion_headings{
    position:relative;
}
.accordion_headings .arrow{
    display:none;
}
.accordion_headings:hover .arrow{
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-bottom: 5px solid red;
    display:block;
    position:absolute;
    bottom:0;
    left:49%;
}

.accordion_child{
    padding:15px;
    background:#fff;
}

.header_highlight{
    background:#a0a0a0;
}

.tab_container *{
    float:left;
    width:100px;
}

</style>