Resize logo in smartphone layout

Hello! I need the help for some questions about the resize the logo image of my web site. I set the logo of my web site bigger than the default size using CSS. Both for PC and Tablet layouts the size it's good for me but the size in the smartphone layout is too small. How can resize logo also for smartphone layout (also during the scrolling of the pages?) Generally speaking what are the functions that regulate the sizes for the three layouts (also during the scrolling)? Finally: is it possible move the logo image upper than the secondary menu? Please refer to home page www.viadellaseta.net Thank you very much. Best regards, Alessandro