Hello,
I wanted to post it from quite a time but, well, did not took it 😁 .
I'm using mainly safari as browser.
Usually, I don't load the forum in full width of my screen but only like 2/3 of it. In this case, if there is a video embedded (pornhub or youtube, both are problematic), the content of the right part of the video is hidden outside the thread width.
In fact, the video width is fixed on the width of screen and not width of the browser window.
Looking at the resource, it indeed seems there are embedded in an iframe whose width is fixed at 640px. I think that the size is doubled (Retina display) which make it double the size of the same page in firefox...
Firefox, full width :
Safari, full width :
Maybe having a look here :
https://jameshfisher.com/2017/08/30/how-...th-iframe/ ?
Or another multi-browser css issue but I'm far from a good web developper so I'll not say what to do as I don't know... 😁