[css3-background] Background positioning area of root element when background-attachment is fixed (original) (raw)

Hi,

http://www.w3.org/TR/css3-background/#special-backgrounds says "the background positioning area is determined as for the root element". However I tested several browsers (Chrome, IE10, Firefox, Safari) and they all seem not to conform this.

Test case is like:

http://jsbin.com/pepufelo/1/ (gradient) and http://jsbin.com/pepufelo/2(real image with background-size: 100% 100%) also allow you to toggle between 'fixed' and 'scroll' background-attachment by clicking on the page.

On my tested browsers, when background-attachment is fixed, the viewport (instead of the root element) is used as the background positioning area. I'm wondering if this behavior has been specified or is a known issue.

Thanks, Xianzhu