Thanks for the link, I've stored it away for future usage.
Maybe I'm missing something - I am entirely new to this - but when the XHTML template is in Kompozer it looks, well, how it's supposed to. But the second I begin to over-type the sample text (not the code, but replacing "header 1" with what I want the header to be) with my own -or, even in one case, change the title- then the design "collapses", or just takes on a basic look, rather than the design that was there previously. (This has happened with every template I've downloaded.)
Clearly I'm doing something wrong, as I thought XHTML and HTML would both be capable of being edited in Kompozer, but for whatever reason it's not quite happening.