JSFiddle - React, Tailwind, and code Playground

HTML

<div class="elastic-object">
	<textarea></textarea>
</div>

CSS

/* figure */.elastic-object {
	height: 0;
	width: 100%;
	position: relative;
	padding-bottom: 56.25%; /* = 9 * 100/16 = 16:9 */
}

.elastic-object > * {
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	position: absolute;
}