I would love to know how to do this. I have very little programming knowledge. I am mainly graphic based. I have a web design for a site, and would like to adapt elgg to the design. How do I overwrite the default index page to include my design with the elements of the page? Is it easy?

After looking through the views, I am getting the feeling that if I change the main css.php file that it will change the look of the entire site. Is this true? of all pages?