If you have not read the first part, you can find it here ( https://coderwall.com/p/nx-uxw )
When you want for example to set a background, it is much more readable to use properties like backgroung-image, background-color or background-size instead of just background. Properties set in multiple lines are much more easy to read.
Third person shooter
Try to read your code as a different person reading it for the first time, if it is understandable, it is ok. Else, change your code. Remember to always write your code as it was written for somebody else.
Blocks & Comments
Sort classes into blocks, if some particular classes are used to style footer put them into one block and make two lines of space before and after. For example:
/* End Header classes */
/* Article classes */
/* End Article classes */
/* Footer classes */
It is stupid to put width value at the beginning of a class and height at the end. Keep similar values or those that work together as close as possible.
Part two is the last :). Please, leave comments or pm me if I made some mistakes.