JSFiddle - React, Tailwind, and code Playground

HTML

<div id="top">1</div>
<div id="mid">2</div>
<div id="bot">3, 4, get that div out the door!</div>

CSS

html, body {
    margin: 0;
    padding: 0;
    border: 0;
}
body {
    color: #fff
}

#top, #mid, #bot {
    position: absolute;
    width: 100%
}

#top {
    height: 20px;
    background: red;
    
    top: 0;
}
#mid {
    background: #000;
    
    top: 20px;
    bottom: 20px
}
#bot {
    height: 20px;
    background: blue;
    
    bottom: 0
}