This is so sad. CSS is so hard to do anything in we have to gush over basic animations like this. It’s sad as a former flash developer.
I've never seen something this seamless and realistic built in flash.
People aren't gushing over this being possible in modern browsers - it's been possible to do this and much more in browsers for many years. They're gushing over it being possible with just CSS (no rendering using JS).
But we're here now and you can do a lot more today with open web tech than was ever possible in flash.