CSS editing and fixing - Cleaning making consistant site wide.

I require cleaning off CSS, consistency through out my site clean light weight code, I am looking for a clean design the same as mailchimp for the headers - Clarification in the CSS - Serious professionals only - only those who can read and don't copy and paste sales pitch about how great they are, any listings with top 10 web sites will be reported as spam. You must mention my job in the details in your bid. I wil be asking for 1 good example of a clean css/html5 site you have doen which is not a template or wordpress / Joomla site etc. Should take one good full day, perhaps a little more.