How to create a full screen video background.
source: w3schools.com
<!-- The video -->
<video autoplay muted loop id="myVideo">
<source src="backgroundVideo.mp4" type="video/mp4">
</video>
<!-- Optional: some overlay text to describe the video -->
<div class="content">
<h1>Heading</h1>
<p>Lorem ipsum...</p>
<!-- Use a button to pause/play the video with JavaScript -->
<button id="myBtn" onclick="myFunction()">Pause</button>
</div>