JSFiddle - React, Tailwind, and code Playground

HTML

<div id="sidenav">
        <ul>
            <li class="subactive"><a href="http://www.inspile.com/services-overview/">Overview<span class="arrow"></span></a></li>
            <li><a href="http://www.inspile.com/engagement/">Engagement<span class="arrow"></span></a></li>
            <li><a href="http://www.inspile.com/website-design/">Design<span class="arrow"></span></a></li>
            <li><a href="http://www.inspile.com/website-development/">Development<span class="arrow"></span></a></li>
            <li><a href="http://www.inspile.com/mobile-web/">Mobile<span class="arrow"></span></a></li>
            <li><a href="http://www.inspile.com/search-engine-optimization/">Search Engine Optimization<span class="arrow"></span></a></li>
          </ul>
    </div>

CSS

#sidenav ul
{
    list-style-type:none;
    margin: 0;
    padding: 0;
    width: 125px;
}
#sidenav a, #sidenav a:visited
{
    border-top-left-radius: 5px 5px;
    border-bottom-left-radius: 5px 5px;
    display: block;
    height: 50px;
    font-family: Futura, ‘Century Gothic’, AppleGothic, sans-serif;
    text-decoration: none;
    padding-left: 10px;
    color: #292721;
}
#sidenav a:hover, #sidenav .subactive a:link
{
    color: #fff;
    background-color: #034676;
}