JSFiddle - React, Tailwind, and code Playground

HTML

<div id="con">
    <div id="big"></div>
    <div id="small"></div>
</div>

CSS

#con {
    position:relative
}
#con, #big {
    width:200px;
    height:200px;
    background:red;
}
#big {
    position:absolute
}
#small {
    position:absolute;
    width:50px;
    height:50px;
    top:75px;
    left:75px;
    background:blue
}