JSFiddle - React, Tailwind, and code Playground

HTML

<footer>Footer footer footer footer footer footer footer footer footer</footer>

CSS

*{
    box-sizing: border-box;
    position: relative;
}

html, body{
    background-color: #D9DADD;
    height: 100%;
    font-family: sans-serif, arial;
}

footer{
    width: 100%;
    max-width: 600px;
    padding: 10px;
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    margin: 0 auto;
    text-align: center;
    font-size: 2em;
    background-color: rgba(0,0,0,.3);
    border: 2px solid #FFF;
    color: #FFF;
    box-shadow: 0 2px 4px 1px rgba(0,0,0,.4);
}