I tried this method earlier but unfortunately faced other problems because it is a sticky header (stays with you if you scroll down). So when you scroll down the settings mentioned above still leave white gaps on the edges. Is there another way to make the header fit the whole screen?
Best Regards
-PS: I also tried another approach of increasing the width of div.site-navigation-inner.col-sm-12, unfortunately increasing the width does not get rid of gaps on the sides, it just widens the page.
div.site-navigation-inner.col-sm-12 {
width:1265px
}