Product Detail Page Header Not extending to Page

Site URL: https://www.baseng.com/new-products/askw

I'm editing the product detail pages through custom CSS, and for some reason the sides of my header are being cut off on my 1920x1080 monitor. They're not cut off on my 1536x864 laptop though... 

This is the code I have in CSS.

.view-item .Header-inner {
  background: #777777;
  width: 100%;

}

I'm not sure if something is making it impossible extend or what's happening. Does anyone know how to extend this header to fit all resolutions? 

Below are screenshots of the two screens. First has the cut off header and second has the full extended header.