JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div id="outer">
        <div id="inner1"></div>
        <div id="inner2"></div>
    </div>
</body>

CSS

#outer {
    display: block;
    position: absolute;
    background-color:Blue;
    width: 100%;
    height: 100%;
}
#inner1 {
    display: block;
    position: relative;
    width:20%;
    height:20%;
    background-color:Black;
}
#inner2 {
    display: block;
    position: relative;
    top:10%;
    width:20%;
    height:20%;
    background-color:Red;
}