The goal is to have min-width: 960px; with centered layout and additional ‘wings’ for bigger screen.
See the current implementation using negative margins: http://dl.dropbox.com/u/8313423/wings.html
The problem is that when the window size is 960px or smaller, there is a horizontal scroll that allows to scroll till the end of yellow div(but should be just till the end of the text). In this implementation horizontal scroll appears when a viewpoint reaches a yellow div, but it should only show up when it reaches the text. It seems to me that the negative right-margin is ignored.
Any ideas how to fix horizontal scroll behaviour?
The problem is that you have 70px of padding on each side and padding is included in the box size. Instead of being 960px wide, it’s 1100px (960 + 70 + 70 = 1100) wide. Even though you have negative margins, the box size is unaffected by those so you will get a horizontal scroll on any width less than 1100px.