CSSlean is tool which will help you reduce size of your CSS file or rearange it so it will be easier to read and easier for maintenance. After you optimize your CSS code your pages will load quickly and tranfer less data, and you and visitors of your web site benefit from this CSS optimization.
Important Note: Your code should be well-formed. This is no validator which points out errors in your CSS code. To make sure that your code is valid, use the W3C Validator.