Originally Posted by leek

CSS does not have ANY affect on SEO. You and your friend are mistaken.

What you are referring to is valid/proper use of HTML tags for semantic purposes. Google and other search engines care about your H tags, strong, em, p, etc. They don't care about whether your text is blue or green. Or whether your DIV is 50px wide.

The reason CSS helps is because you can use all of these tags while still maintaining the look and feel of the design of your page.

And by the way - you made yourself look like a complete tool with this quoted response.