JSFiddle - React, Tailwind, and code Playground

HTML

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

CSS

body, html {
    width: 100%;
    height: 100%;
    
}

body {
    background: pink;
}

.center {
    width: 64px;
    height: 36px;
    background: red;
    
    position: absolute;
    top: 50%;
    left: 50%;
    margin-left: -36px;
    margin-top: -18px;
}