JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test"></div class="pippo">

CSS

#test {
    position: relative;
    border: 1px solid blue; margin: 10px;
    width: 80%; height: 30px;
    cursor: pointer;
}

.pippo {
    content: " ";
    display: inline-block; width: 20px; height: 20px;
    position: absolute; top: 5px; right: 5px;
    background: red;
}

#test:hover:before {
    background-color: green;
}