Stretching navbar on fixed Width to fluid size?

[Inked_Mono]

Does anybody know if there's a way to stretch the navigation bar and the banner beyond the parameters of the fixed width?

So, from this:

To this:

That's editing the CSS to use margins, but I'm wondering... is there a way to make it fluid with the browser? In the same sense that setting the forum width to 70% would keep it a fluid 60% regardless of dimensions.

--------------- Added [DATE]1457392840[/DATE] at [TIME]1457392840[/TIME] ---------------

I was able to figure it out.

I set the stylevar for the doc_width to 100%, while assigning the following traits to the .body_wrapper CSS template.

    width: 65% !important;
    margin-left: auto;
    margin-right: auto;

[hazem_aliraqi]

try this

.above_body {
margin-left: -35px;
 margin-right: -35px
}