JSFiddle - React, Tailwind, and code Playground

HTML

<div class="outer">
    <span>Outer</span>
    <div class="inner">
        <span>Inner</span>
    </div>
</div>

CSS

.outer {
    width:80%;
    height:500px;
    background:#eee;
    position:relative;
    text-align:right;
}
.inner {
    position:absolute;
    top:0;
    bottom:0;
    width:50%;
    background:#aaa;
}