JSFiddle - React, Tailwind, and code Playground

HTML

<div class="center"></div>

CSS

.center {
   width: 300px;
   height: 300px;
   position: absolute;
   left: 50%;
   top: 50%; 
   margin-left: -150px;
   margin-top: -150px;
   background-color: red;
}