JSFiddle - React, Tailwind, and code Playground

HTML

<div id='wrapper'>
  <div id='block'> I'm Block </div>
  <div>

CSS

#wrapper {
  border: 1px solid red;
  width: 500px;
  height: 500px;
}

#block {
  border: 1px solid blue;
  width: 500px;
  height: 250px;
  position: relative;
  top: 50%;
  transform: translateY(-50%);
}