JSFiddle - React, Tailwind, and code Playground

HTML

<div class="page-wrap">Content!</div>
<footer class="site-footer">I'm the Sticky Footer.</footer>

CSS

* {
    margin: 0;
}
html, body {
    height: 100%;
}
.page-wrap {
    min-height: 100%;
    /* equal to footer height */
    margin-bottom: -142px;
}
.page-wrap:after {
    content:"";
    display: block;
}
.site-footer, .page-wrap:after {
    /* .push must be the same height as footer */
    height: 141px;
}
.site-footer {
    border-top: 1px solid #666;
    background: #eeeeee;
}