Looks really great overall - props! One small design thing in there that bothered me was how the gradients reverse in the buttons on hover - this should never happen. Just lighten or darken the color on hover (move the gradient up with background position and add a transition is a good trick), then consider reversing the gradient on active (or just adding an inset shadow).

Everything else in the design looks great and this is totally nitpicky, but hope it helps!