Removing top of background and extra white space around header

Hi, I'm trying to do two things to my website (arcturusastrology.com), and I've searched this forum for code to put into the custom CSS box in the "Theme Options" setting, but nothing changes. I'm using a child theme, so hopefully this is not an issue with my setup. Here's what I'm trying to do. I've already changed the settings of the margins for the header to 0 in the "Theme Options": 1. I'd like to remove the top part of the background so that the header is at the very top of the page. Is there a way to do that? 2. I still see a bit of a white box above my header and to the left. What can I do to get rid of these? Any help you can provide will be most appreciated!