Are you saying the -webkit- is giving you invalid error?
-webkit- is a vendor extension. Don’t worry about it being invalid. There are errors which are acutal errors and need fixing, then there are errors which you don’t need fixing. The validator only validates based on what it knows. It doesn’t know the vendor extensions so it’s “invalid” but you can still use it. Especially for newer code that’s new in CSS.
You also need a version of the keyframes without -webkit. You do understand that that keyframe code you posted will only work for webkit browsers? CHrome and Safari?
Nope. Only -webkit-. That’s why you see in the CSS that there is a -webkit- version and then the regular way right under it. -webkit- only is recognized by -webkit browsers. All others ignore it. So right now, only chrome/safari will see it. Firefox and IE will brush over the code and pretend it doesn’t existed. It’ll pretend like you’re the nerd and the browser is the popular girl in school. Won’t give you (the -webkit-) a second thought .
Put the keyframe back to what the original webpage that you took this code from has. It has more than just 60%. Not sure why you deleted hte other percentages.