JSFiddle - React, Tailwind, and code Playground

HTML

<div id="k9nav-inner">
    <ul>
        <li>this is an li</li>
    </ul>
</div>

CSS

#k9nav-inner ul li:hover {
    display: inline-block;
    box-shadow: 0 2px red;
}

#k9nav-inner ul li {
    display: inline-block;
    list-style: none; 
}