JSFiddle - React, Tailwind, and code Playground

HTML

<nav></nav>
<article>Lorem ipsum...</article>
<footer></footer>

CSS

html {
    position: relative;
    min-height: 100%;
}
body {
    margin: 0 0 100px; /* bottom = footer height */
}
footer {
  background: red;
    position: absolute;
    left: 0;
    bottom: 0;
    height: 100px;
    width: 100%;
}