JSFiddle - React, Tailwind, and code Playground

by Curry

HTML

<div id="outer">
    <div id="inner">
        This div is centered both ways and 150x200 pixels in size.
    </div>
</div>

CSS

#outer {
    position:fixed;
    top:0;
    bottom:0;
    left:0;
    right:0;
}
#inner {
    position:absolute;
    height:200px;
    width:150px;
    top:50%;
    left:50%;
    margin:-100px 0 0 -75px;
    background:#eee;
    border:1px solid #ccc;
}