JSFiddle - React, Tailwind, and code Playground
HTML
<!--[if lt IE 9]>
<script>
document.createElement('video');
</script>
<![endif]-->
<video autoplay loop muted id="video-bg">
<source src="http://demosthenes.info/assets/videos/polina.mp4" type="video/mp4">
</video>
CSS
#video-bg {
position: fixed;
right: 0;
bottom: 0;
width: auto;
min-width: 100%;
height: auto;
min-height: 100%;
z-index: -100;
background: transparent url(video-bg.jpg) no-repeat;
background-size: cover;
}
video {display: block;}