Full Screen Player Proportions on Small Accessory Monitor

[gradyworld]

I have a small accessory monitor of which I like to show now playing and lyrics on while I am working. That small monitor is 1200x600 (although it's not perfectly that size). When using the full screen player on that small monitor, the proportions leave wasted space and data extends past the tab width.

A couple of screen shots are attached, but I was hoping there was some way to tweak the look with custom .css in settings. I am not sure, however, of what divs, classes, etc are used for the full screen player. I searched for a reference but couldn't find it.

Can someone provide one or give another suggestion that might work?

Thank you in advance.