Interface width

[victorbnl]

Is your feature request related to a problem? Please describe.
The interface is way too big by default I think, at least on my computer, so it should at least manage the zoom correctly

Describe the solution you'd like

Additional context
It seems easy to do, the first thing would be to set justify-content: center on #playing-div, and then find another way to manage the width of the interface

[busybox11]

This might be a good idea. It's going to be pretty easy to implement, I'm going to take a look at it!

[finnie2006]

You should make it an option, but not by default