JSFiddle - React, Tailwind, and code Playground
HTML
<div class="parent">
<div class="inner-content" id="inner1">
Mauris mauris ante, blandit et, ultrices a, suscipit eget, quam. Integer ut neque. Vivamus nisi metus, molestie vel, gravida in, condimentum sit amet, nunc. Nam a nibh. Donec suscipit eros. Nam mi. Proin viverra leo ut odio. Curabitur malesuada. Vestibulum a velit eu ante scelerisque vulputate.Mauris mauris ante, blandit et, ultrices a, suscipit eget, quam. Integer ut neque. Vivamus nisi metus, molestie vel, gravida in, condimentum sit amet, nunc. Nam a nibh. Donec suscipit eros. Nam mi. Proin viverra leo ut odio. Curabitur malesuada. Vestibulum a velit eu ante scelerisque vulputate.
</div>
</div>
CSS
.parent{
background:black;
padding:20px;
position:relative;
overflow:hidden;
height:250px;
width:700px;
}
.inner-content{
background:gray;
}
#inner1{
width:6000px;
height:5000px;
}
JavaScript
$(".parent").each(function(){
// get parent height
var p = $(this).css("padding").replace("px","");
var h = $(this).css("height").replace("px","");
var ph = h-2*p;
// get inner height
var $ic = $(this).find(".inner-content");
var ih = $ic.height();
// set zoom size
$ic.css('zoom',ph/ih);
$(this).height(ph);
});