Why does user agent stylesheet override my styles? [closed]

Answer 1

This might sound odd, but it helps to check (especially if you aren't using an IDE or one that doesn't do validation on your CSS). You might want to make sure that you have a ; and not a : at the end of your:style; line. Because at a glance, in the inspector the syntax appears to be correct but isn't. So your user agent stylesheet overwrites it. It's one of those "make sure your printer is plugged in" checks. It happens to all of us every once in a while.

Answer 2

This is an outside shot without your code, but the solution when I had the exact same problem. My DOCTYPE statement had gotten fouled up by an errant keystroke, as described in this question. You might want to inspect it visually and/or validate.