JSFiddle - React, Tailwind, and code Playground

HTML

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

CSS

div.parent {
    position: relative;
    height: 500px;
    background: blue;
}
div.child {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 200px;
    background: green;
}