Css and Drupal

You can build a very simple or quite complex site with Drupal. That's one of the advantages. You are not locked in, as you might be with other CMSs.

For my first Drupal site, I had to take the css and xhtml from an asp-based university site and adopt it to Drupal for a university program site. I have no PHP background. I have coded sites since 1996; started with hand-coding; ended with Dreamweaver. I'm now hooked on Drupal.

In answer to your questions:

1. Yes and no. If you want to use a css file without making a single change to it, I guess it's possible but I doubt it. If you are asking, would you be able to recreate the design of a site, the answer is 'yes.' Same thing with your xhtml file.
2. I have only read about Joomla so I can't answer an import question. But the first part of your question helps me understand where you are confused. So let me explain in more detail...

Let's say you want one "look" for every page of your site...an easy site to build. You could use your xhtml and your css file. You rename your xhtml file "page.tpl.php" and your css file becomes "style.css"

Then you begin the process of modifying your page.tp.php for Drupal. You do that by inserting php code. For example, instead of building your left nav bar in your html file, you insert: print $left

That bit of php will print to the screen all of the blocks of content that you have indicated, via the Drupal administration area, are to be displayed in the left region.

The variables available to you are listed here on the Drupal site. It's also handy, I felt, to get one of the themes -- say Garland or zen -- and to look it over. I discovered many of my how-to's from looking at the page.tpl.php of those themes. They have html code in them with php calls. They're not so mysterious once you open them up and study them.

There are many occasions when I found myself adding to my css file. However, that doesn't mean that I changed the overall site design from what the university mandates. When I used panels for landing pages (highly recommend panels and views), I noted that the html has classes in it -- or you can add classes, ids. The classes that you have been provided can be styled in your css file. So, what I am saying is that it might be onerous to add your css selectors to the code generated but there's no reason you can't take the drupal created selectors and give them your style. Easy as can be.

This is a very simple reply. But, I hope it helps. I encourage you to do Drupal. It can be a real hair-puller at first but once you have passed the early learning stages, you'll suddenly go "wow, this is cool."