JSFiddle - React, Tailwind, and code Playground

HTML

<html>

<head>
        <title>This is My Page's Title</title>
</head>
<body>
        <div id="leftrightparent">
                <div id="left">
                        left
                </div>
                <div id="right">
                        right
                </div>
        </div>
</body>

 </html>

CSS

body{ width: 100%; }
#left {
  display: table-cell;
  background-color:#ff0000;
}
#right {
  display: table-cell;
  width:180px;
  background-color:#00FF00;
}
#leftrightparent {
    display: table;
    width: 100%;
}