JSFiddle - React, Tailwind, and code Playground

HTML

<button>Click me</button>
<div></div>

CSS

button{
  position: relative;
}
div{
  width: 200px;
  height: 200px;
  background: aqua;
  display: none;
  position: absolute;
}
button:focus div{
  display: block;
}