Not dumb at all! It's a common shorthand around here because in vim (and presumably other text editors) that is the syntax for replacing strings - in this case, replace "webkit" with "moz". It was a useless comment on my part. What I meant (and should have said) is that merely removing the vendor prefix "webkit" wouldn't make it work with Mozilla, but replacing it with "moz" probably would. (I'm not certain about the details of Mozilla's feature parity with Webkit when it comes to CSS animations but I suspect they are almost equal.)