JSFiddle - React, Tailwind, and code Playground

HTML

<div id="bottom">bottom</div>
<div id="top">top</div>

CSS

#bottom, #top
{
    position: absolute;
}
#bottom
{
    top: 25px;
    left: 25px;
    background-color: blue;
    color: white;
    font-size: 20pt;
    height: 150px; 
    width: 150px;
}

#top
{
    top: 0px;
    left: 0px;
    background-color: red;
    color: white;
    font-size: 20pt;
    height: 200px; 
    width: 200px;
    opacity:0.4;
    filter:alpha(opacity=40); /* For IE8 and earlier */
}