how to add a body class to a page template

I discovered I don't need a body class to accomplish what I'm trying to do, I can just use a really specific selector pulled from the page source. But I cant get it to keep from overlapping the footer widget area. How can I get a 100% width just in the content area of a single page?

-Chad

You could do something like this:

.my-specific-selector .container.grid-container {
    max-width: 100%;
}