Remove Border around content & Decrease margin around content

Hi guys, I'm making some changes and there are a couple of things I am hoping you can help with? 1. Is there a way to remove the border around the main content area of the page? I've attached a photo to show you exactly what I mean. I've made the background all white but I'd love for there not to be any line of separation between the background color and the main content area. 2, Also, Is there a way to decrease the margin around the main content area of the page? You can also see what i mean in the photo. You can see the screenshot of what I mean here: https://s29.postimg.org/agq4s94br/Screenshot_AFF.jpg Thank you!