JSFiddle - React, Tailwind, and code Playground

HTML

<div id="floatbar">
    <a href="" onclick="make it float 10px under this yay">Link</a>
    <div class="box">Popup box</div>
</div>

CSS

.box {
     display:none;
     position: absolute;
     top: 30px; 
     left: 10px;
    background: orange;
    padding: 5px;
    border: 1px solid black;
}

a:hover + .box {
     display:block;   
}