问题
Not sure what is going on. The hover effect on the page below is very slow to respond in Firefox. When you scroll, the page is not smooth either. This particular page runs smoothly in other current browsers. The site is very fast so I am not sure what to think.
http://thebc.co/our-work
来源：https://stackoverflow.com/questions/13304218/grayscale-hover-effect-slow-in-ff-fast-in-chrome-ie-and-others