aww okay, let's see
I mean, it happens to me a lot, that something is not working, and then I realize I made a typo like "colour" instead of "color" or I used a colon at the end of a line instead of a semicolon. So sometimes you're doing something actually right, but it's just a typo that makes it not work. I always double check what I write
It's a bit hard to help, without knowing what you are exactly trying to do. Generally though, most things should work on all browsers and I haven't come across somethign that is no longer supported by DA; (there is some CSS3 that is not supported on DA yet).
Sometimes what you want to achieve requires two classes to work together and it can easily happen you forget one.
You can reply here or note me with your problem, whatever you prefer