About a wide screen google mup on Upfront

Hi, I'm trying to setup a page with whole wide screen google map, I would like map to appear like images do in a wide screen, from left edge to right edge, in this way: http://lecascatedisaturnia.com/le-cascate-di-saturnia/
but I just obtain contained maps, I cannot find a control to have map running from edge to edge; worst is in mobile screen where maps are worst narrows for this reason