<video controls autoplay muted loop>
<source type="video/webm" src="https://sageptr.github.io/sageptr-test/beachball.webm" />
</video>

html {
  background: #111;
  background-image: linear-gradient(45deg, #222 25%, transparent 25%), linear-gradient(-45deg, #222 25%, transparent 25%), linear-gradient(45deg, transparent 75%, #222 75%), linear-gradient(-45deg, transparent 75%, #222 75%);
  background-size: 30px 30px;
  background-position: 0 0, 0 15px, 15px -15px, -15px 0px;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}