JSFiddle - React, Tailwind, and code Playground

HTML

<article id="content">
<p>Hello, World!</p>
</article>
<nav id="sidenav"><ul>
    <li>nav</li>
    <li>nav</li>
    <li>nav</li>
</ul></nav>

CSS

#sidenav { position:absolute; top:0; left:0; width:150px; height:200px; background:red }
#content { margin-left:150px; background:url(http://phrogz.net/tmp/grid.gif); height:300px }