Mats, I’m not sure why Firefox is squawking about that CSS, but I’ll look into it; thanks for the heads-up. For what it’s worth, the validator doesn’t seem to complain too loudly.

And Maarten, Alan’s suggestions are spot on. You could take his modifications and use them as the basis for any number of improvements, such as rollovers and a “current tab” state (see the second Sliding Doors article for examples on how to do this).

Thanks for the feedback, all. Glad you liked the tip!