One small thing in the latest redesign: if you have two tabs, one active, one not, the visual cues suggest exactly the opposite. The active one seems like a clickable button, the inactive one seems pushed down and not clickable.

After misclicking hundreds of times, I still couldn't train myself to go against my perception and follow the designer's "bold vision", using it feels like writing with my left hand or steering a bicycle with a crooked wheel.