David,
from my experience it is from easy to create cross browser compliant
CSS based pages. There are many differences and idiosyncrasies between
even the most recent versions of Mozilla, IE and Opera. Not to mention
the differences within the same browser of the same version across
various platforms.
What might work in one browser, on one page might not necessary work
on a different page using the same CSS classes an IDs but with
(slightly) different HTML.
Now, don't get me wrong, I do think that CSS is the way to go. But be
aware that CSS support even in today's browsers fluctuates
significantly.
Creating a style sheet for ETP that works with all ETP content will
require a conservative approach. Stick to CSS 1 where possible as
browsers support this CSS version the best. And even then you'll have
to test your style sheet extensively.
Ask your self which browsers and platforms you intent to support.
/Bart
