Bu this still not solving "YouTube videos are too large on mobile devices" the original problem in this thread. Other than this CSS (and ignore the important warning) , should o do anything else to solve the original problem ?
[Solved] YouTube embed not working on 0.41
It was working fine earlier. But as you can see in the thread below. It has stopped autoembeding YouTube links
marking this as solved (https://community.nodebb.org/topic/1332/youtube-embed-not-working#9734)