JSFiddle - React, Tailwind, and code Playground

HTML

<table id="outer"><tr><td id="td"><table id="inner"><tr><td><div id="square"></div></td></tr></table></td></tr></table>

CSS

#outer  {
    width: 100%;
    height: 400px;
    border: 1px solid #efefef;
    
}

#square {
    width: 100px;
    height: 100px;
    border: 1px solid #ccc;
    position: absolute;
    bottom: 0;
    right: 0;
}

#inner {
    width: 300px;
    border: 1px solid #999;
    height: 300px;
    position: relative;
    display: block;
}