DO NOT Forget that CSS is Case Sensitive

I was working on a web page with couple of div tags that are absolutely positioned in the page. When I added the footer to the page, it was displayed way at the top of the page rather than at the bottom. This is when I noticed that my absolutely positioned elements are outside my center aligned website main body content area.

I literally spent couple of hours trying to figure out why the absolutely positioned elements are outside my body content area. I tried rearranging the elements, removing elements and all kind of trial & error options but no change. Finally after couple of hours, when I was about to give up, I noticed that my CSS Class name was defined as "main" and I was using "Main". That single case sensitive class name was screwing up my page!

Lesson learned - DO NOT FORGET CSS is Case Sensitive!