JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrap"><div id="inner"></div></div>

CSS

#wrap {
    width: 100%;
    background: #ccc;
    position: relative;
    min-height: 20px;
}

#inner {
    width:30%;
    background: #000;
    position: absolute;
    right: 0;
    top: 0;
    height: 200px;
}