JSFiddle - React, Tailwind, and code Playground

HTML

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

CSS

html, body {
    height: 100%;
}
.c {
    background: grey;
    width: 50%;
    height: 50%;
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
}