space between header image and the primary menu

Hi, I use the 1128x162 px header image and it seems that there's too much space between the header and the primary menu so the slider images does not fit on the PC screen. How can I fix it so that I don't have to scroll down to see the slider? Another question, how can I change the font size in feature content? I think it's a bit too big. Anyway, the theme works fine on mobile devices. Love it! Here's my homepage http://www.ee.eng.up.ac.th/engup2558/ Thanks