Small UI Bug with audio control
When you choose the dark window style, and click down the 'mute' or 'maximum volume' at the bottom controls, then you see a grey background color, which does'nt fit in the UI style.
Furthermore I want to suggest something for the mute button: If you click them, for the user I'ts not really clear what happens. As the volume slider does not change, I would consider using a different picture for the mute button:
Perhaps you can put a cross inside to indicate that this is a mute button and not 'decrease volume' or something else. And furthermore perhaps you can change the picture to something like the blue shuffle and random buttons to indicate when the mute is now active. Just my thoughts.
Anyway, thanks for your great work on the UI.