JSFiddle - React, Tailwind, and code Playground

HTML

<div class="outer">
    <div class="inner">
        //some stuff<br/>
        //some stuff<br/>
        //some stuff<br/>
        //some stuff<br/>
        //some stuff<br/>
        //some stuff<br/>
    </div>
</div>

CSS

.outer {
height: 100%;
    position:absolute;
border:1px black solid;    
}

.inner {
 position:relative;
border: 1px red solid;
top: 50%;
bottom: 50%;    
}