如何在浏览器窗口高度100％处设置div，但是具有顶部和底部边距？

More specifically, I have a right sidebar that spans the right side of the browser window. That part hasn't presented any problems. However, I want it to contain a div that is also 100% of the browser height, but with a top and bottom margin. The contents inside this div will scroll if the content won't fit within the browser window height. I can't get it to work. Here is my code:More specifically, I have a right sidebar that