JSFiddle - React, Tailwind, and code Playground

HTML

<body>
<div class='container'>
  container stuff
</div>
<footer>
  footer stuff
</footer>
</body>

CSS

body {
    min-height: 100%;
    padding-bottom: 200px;
    position: relative;
}
footer {
    position: absolute;
    bottom: 0;
    height: 200px;
    left: 0;
    right: 0;
}

/* just for show */

.container {
    height: 1000px;
    border: 1px solid green;
}

footer {
    border: 1px solid blue;
}