JSFiddle - React, Tailwind, and code Playground

HTML

<nav>navigation</nav>
<div>main content</div>
<footer>Footer</footer>

CSS

nav, div, footer{
    border: 1px solid black;
}
nav{
    background-color: steelblue;
}
div{
    background-color: orange;
    height: 300px;
    /* height: 600px; */
    margin: 20px 0;
}
footer{
    position: absolute;
    bottom: 0;
    width: 100%;
    background-color: green;
}