Learn how to embed YouTube videos responsively and without increasing the page load time. The embeds are light and mobile friendly and the YouTube player is loaded only when the user initiates the video playback.
As a fan of reducing the weight of pages, I dived right in. Something stood out to me, however, that I saw an opportunity to improve.
In the interests of progressive enhancement I made three quick changes to his code:
I added a style so that any links in the box are white (look for .youtube-player a in the CSS)
Into the box I added a plain text link to the video at YouTube.
I compressed and then converted the play button to a base64 data URL (removing a possible 403 from imgur and an extra request).
Mike, I see from your notes that you tested it across browsers, but what assistive technology did you use? I ask because at a glance I see some odd use of roles and document structure. I forked it so that I could run it in Debug Mode in CodePen, making it easier to check with a screen reader: https://s.codepen.io/aardrian/debug/amwmPK
I would be interested to see the results from the accessibility testing you have commissioned. Please let us know how it fares.