JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>About</li>
     <li class="active">Share</li>
     <li>Add To</li>
    <div class="clearfix"></div>
</ul>

CSS

ul {
    list-style: none outside none;
}
ul li {
    border-bottom: 20px solid #DDDDDD;
    cursor: pointer;
    float: left;
    margin: 0;
    width:100px;
    height:50px;
    line-height:50px;
    position: relative;
    text-align:center;
}
.clearfix {
    clear: both;
}
ul li:hover:after,
ul li.active:after{
    border: 1px solid red;
    bottom: 0;
    content: "";
    left: 0;
    position: absolute;
    width: 100px;
}