JSFiddle - React, Tailwind, and code Playground

HTML

<div class="first_bg"></div>
<div class="second_bg"></div>

CSS

body, html {
    height: 100%;
}

div{
    height:50%;
}

.first_bg{
    background: red;
}
.second_bg{
    background: green;
}

*{
    margin:0;
    padding:0;
}