JSFiddle - React, Tailwind, and code Playground

HTML

<div id="a">testtesttesttesttesttesttesttesttesttest
testtesttesttesttest
testtesttesttesttest
testtesttesttesttest
testtesttesttesttest
testtesttesttesttest</div>

CSS

#a {
    width: 100px;
    height: 200px;
    overflow-x: scroll;
}

#b {
    position: relative;
    left: 0;
    bottom: 20px;
    width: 100%;
    height: 20px;
    background-color: white;
}

JavaScript

var overlap = $('<div id=b>');

$("#a").wrap($('<div>'));

$("#a").parent().append(overlap);