JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="inner"></div>
</div>

CSS

.container{
    position:fixed;
    width:100px;
    height:100px;
    top:0;
    right:0;
    bottom:0;
    left:0;
    margin:auto;
    background:green;
    padding:10px;
}
.inner{
    height:150px;
    background:red;
}