JSFiddle - React, Tailwind, and code Playground

HTML

<div class="left-box"></div>
<div class="right-box"></div>

CSS

.left-box {
    width: 100px;
    height: 100px;
    background-color: red;
    display: block;
}
.right-box {
    width: 100px;
    height: 100px;
    background-color: blue;
    display: block;
}