2px border the background 2 colours, though it's not too important.
Header needs to be sharper, maybe the anti aliasing method's wrong? (set to crisp/sharp)
Underlining of the subheader (the serif font one) looks odd, possibly closer to font and a light grey.
Biggest mistake is with font/fontstyles - try stay consistent.
Consistency means a lot in font styles, and as an example, the capitalised serif font/sans serif font/normal serif font and everything doesn't work together. Whilst a combination of two fonts may be alright, it doesn't go in this case, since there're too many different font styles).