JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <div id="right">Right, fixed</div>
    <div id="left">Left, fluid <br/><br/><br/>...</div>
</div>

CSS

html, body, div { margin: 0; padding: 0; border: 0 none; }
#left { margin-right: 150px; background: lightblue; }
#right { width: 150px; float: right; background: lightgreen; }