JSFiddle - React, Tailwind, and code Playground
HTML
<html>
<body>
<div tabindex="0" class="link">link</div>
<div class="popup">popup text</div>
</body>
</html>
CSS
.popup{
border: 1px solid black;
background: white;
width: 100px;
height: 50px;
position: absolute;
left: 0;
right: 0;
top: 0;
bottom: 0;
visibility:hidden;
opacity:0;
transition:visibility 0s linear 0.2s,opacity 0.2s linear;
}
.link:focus ~ .popup{
visibility:visible;
opacity:1;
transition-delay:0.1s;
}