Brine family - full bleed banner and constrained site body

Hi everyone,

I use the Maple template - part of the Brine family - and am trying to figure out how to keep my hero banner and header to the full width of the screen, while keeping the body content constrained. I've tried using the following: 

body {
    max-width: 960px;
    margin: 0 auto;
}

This does change the content to the width I want it at, but unfortunately also squishes the hero banner into the same size. Is there any way I can achieve the look I want without using spacers on the page?

Thank you in advance!