JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <div class="inner">This div should scale with the browser, and maintain the same aspect ratio.</div>
</div>

CSS

#container {
    background-color: #666;
    color: #ccc;
    padding-top: 23%;
    height: 0;
    overflow: hidden;
}
#container .inner {
    position: absolute;
    background-color:magenta;
    object-fit:cover;
    top: 20px;
    left: 20px;
    right: 20px;
    height:50vh;
    width:50vw;
    z-index: 1;
    font-size: 11px;
}