JSFiddle - React, Tailwind, and code Playground

HTML

<div id="a">
    <div id="b"></div>
</div>

CSS

#a {
    width: 35%;
    height: 300px;
    background-color: #c64800;
    float: left;
}
#b {
    padding-top: 53%;
    background-color: blue;
}