Setting width doesnt work on most stuff??

"width: (number)px;" doesnt really work on most stuff? for instance, the spacehey logo.
only thing ive found that does, is "max-width: (number)px;" although you cant make things
bigger with that, only smaller. how am i supposed to make stuff bigger instead??


im currently trying to make this layout, but the nav.top.center is too short, and i dont know how to extend it.