Web应用程序和使用绝对布局

I'm working on a web app that I want to operate more like a standard OS app. It is similar in layout to iTunes where I have a top header, a menubar beneath it, and then a left-sidebar and a main content area. The goal is that everything stays where it's at on the screen and only the main section scrolls (because it has a grid/table of content).I'm working on a web app that I want to operate