<p>The video timer at the bottom of this page should only start counting when you scroll it into view.</p>

<video src="https://jsbin-user-assets.s3.amazonaws.com/simevidas/time.mp4" muted autoplay playsinline></video>

body {
  max-width: 24em;
  margin: auto;
  padding: 1em;
}

p {
  font-family: Georgia, serif;
  font-size: 1.25rem;
  line-height: 1.4;
  margin-bottom: 200vh;
}

video {
  width: 100%;
  height: auto;
  margin: auto;
}