Enthusiastic noob here. I can usually fathom what is going in these neat CSS demos, but this one baffles me. Could someone provide a few pointers as to how it's doing what it does?
Each rain drop takes an image, scales it down, rotates it 180º, positions it according to the drop's position and crops in a round shape. Then a small border is added according to the drop's size. The trick is getting all those values right.