JSFiddle - React, Tailwind, and code Playground

HTML

<div id='centerred_block'>Я нахожусь ровно по центру экрана</div>

CSS

#centerred_block {
color: #000;
background: #FFF;
border: 1px solid #000;
width: 600px;
height: 400px;
position: absolute;
left: 50%;
top: 50%;
margin-left: -300px;
margin-top: -200px;
}