[codez]

Also, the main point of this is just to make a super simple CSS implementation that requires little JS to work.

Because on the js side you are still having to call a start function and a done function and whatever else you need which is the same as being able to do this with just CSS and then just doing a one liner in js that sets the attribute or adds a class.

Also with progre(c)ss you are only needing one file and people can quite easily change the attribute without having to load in a js file.