Let's establish this first off: I am a typeface nerd, and I, like many, love Helvetica. I'm no pro with CSS, but I wrote up a little style sheet which I told Safari to use which replaces typefaces with Helvetica. However, I couldn't get it to do exactly what I want: rather than replacing all typefaces with Helvetica, I just want to replace Arial with it. My reasoning is that Arial is a slightly-off knockoff font, which was designed to be the same size as Helvetica, so, replacing it should only make things look better. What is a style sheet that would do just what I want?