JSFiddle - React, Tailwind, and code Playground

HTML

<div class="gray"></div><div class="red"></div>

CSS

.gray, .red{
    display: inline-block;
    height: 15px;
}
.gray{
    background-color: gray;
    width: 40px;
}
.red{
    background-color: red;
    width: 60px;
}