So if you take it seriously you probably should make an effort to write it correctly. Now there is CSSLint to add to JSLint and others that will scan though your CSS and "hurt your feelings" by pointing out your poor coding. You can try it out by pasting your CSS into the web site, click LINT! and you will see a list of shameful errors that you need to correct listed.
The only problem is that some of the rules used to determine "good CSS" you might want to argue with - the most obvious being "Don't use IDs in selectors". If you want to know the whys and wherefores of the rules in detail then see About CSS Lint.