Is it common to have a lot of these warnings in CSS validation results:
You have no background-color set (or background-color is set to transparent) but you have set a color. Make sure that cascading of colors keeps the text reasonably legible.

I get this error with this code

Do I really need to state a background color when the the <h>s look fine on the site and the background color for the whole main section that ises these <h>s is already set?