CSS deals with formatting or display of the webpage. It doesnt really have much implication when it comes to SEO. Unless for stuffs like...if u try to format a text that has the same background color to trick the users. Webmasters used to pack keywords in the web page by hiding the text from the user but not from search eninges. search engines usually don't like that and may penalize your site ranking.
but generally, ur right that CSS helps the crawlability for the SE bot!