lucy24 - 9:16 pm on Aug 6, 2011 (gmt 0)
4.01 Transitional is always safe. If you are curious about the CSS you can feed any url into the mobile version [validator.w3.org] of the html validator. They'll scream about any feature that wasn't in CSS1. Take it with a grain of salt though: an iPad for example can probably take everything you throw at it.
The validator doesn't ask if you own a site. Counting errors in the competition's pages is a time-honored form of innocent amusement.