Just another suggestion, a bit of a nitpicking one....
At the moment, when you mouseover the ModernMix 'icon' on upper right in full screen mode, the option to close or to switch between window/fullscreen is shown. I think it would be very handy if you just simply had the close option visible always, beside/above the current icon. Or even better, just get rid of current icon and the close and switch options permanently visible.
I ask because currently you can easily move mouse upto far corner to view option, however to close, you have to delicately pull back the mouse a little to get at the close button. An easier solution to this might be swap the position of the close and switch icons on full screen mode, currently close on the left and switch on the right (and also reduce the border separating the blue close and switch icons and the screen edge) to reduce mouse travel distance.