For those that want a better (IMO) code tag and h3/header3 tag, I suggest adding this to the custom CSS:
Especially the styling for the pre, as the default one is just unusable. This gives it a nice shade, a little space on the sides and removes huge whitespace above and below (that was driving me crazy while editing).
And an H3 should still be "bold", in my opinion :)
Maybe it's useful for anyone.