When adding an audio element to a website in earlier Firefox versions you could set the width of the audio element like this:
<audio controls style="width: 500px">
<source src="x.mp3" type="audio/mpeg">
</audio>
However now this is not possible any longer. No matter if I set 500px or 600px the player always has the same width. This was not a problem in earlier Firefox versions.
Is there something I did wrong or is it a Firefox bug? In Chrome for example everything works.
It's a bug with the new firefox, i just tried out on version 55 it worked and then I upgraded to version 56 and now it doesn't, u may have to wait for them to fix the bug for the time being, or u can send them a bug issue. If any update I'll edit my reply but for now you can consider sticking with other browsers. Edit: I have just sent them a bug report. should be fixed anytime now, be sure to check and update your ff browser.
It appears that it will be fixed in FF57 - it's not showing up in the betas, so whatever was broken, it's already been hunted down and corrected.
Here's the bug report I posted (couldn't find another one): https://bugzilla.mozilla.org/show_bug.cgi?id=1409552