[omegavesko]

>WAY too much CSS to do something like that. I'm not sure what the fix is though? A JS library to generate the CSS animation with a saner syntax (I realise CSS probably needs all of that stuff to be extendable but it's a massive amount of code for something that should be easier to accomplish IMHO).

The most logical solution would be the way we extend CSS syntax today - preprocessors like LESS and SASS. You don't need to render the valid CSS clientside, you can just compile it into CSS before you deploy it.