JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
  <div class="child">

  </div>
</div>

CSS

.parent {
	  position: relative; /*or absolute*/
	  width: 320px;
	  height: 240px;
	  background-color: lightgrey;
	}
	
	.child {
	  width: 64px;
	  height: 48px;
	  background-color: darkgrey;
	  position: absolute;
	  top: 50%;
	  left: 50%;
	  transform: translate(-50%, -50%);
	}