I don’t like the box look that seems so popular, I think it wastes too much space. Can you create a site that takes up the entire window?
Absolutely, however there are some limitations that we would need to deal with, the most important being how your site will look at all sizes of screen and settings.
We can also do what might be called a “faux” screen, where it appears the entire page is utilized when we get to keep control of the size and therefore control of the appearance.
Last, having too much content and not enough space on a web site is not a problem we encounter all that often.