Align header image top-right, above menu

Hi, I'm experimenting with the Catch Evolution theme (which I find pretty awesome so far). Now I'm trying to achieve something probably quite simple, but since I'm new to CSS, any help would be much appreciated: * I want my logo image in the top-left corner (just as it is by default) * I want my header image in the top-right corner, in line with the logo (and not underneath it, which is the standard) * If viewing screen size is reduced (like on a phone) I would prefer if the header image would move to underneath the logo How do I go about modifying the CSS?