JSFiddle - React, Tailwind, and code Playground

HTML

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

CSS

body, html {
    width: 100%;
    height: 100%;
    overflow:hidden;
}
.center {
    left: 50%;
    top: 50%;
    width: 200px;
    height: 200px;
    margin: auto;
    background: #ddd
}