How to handle sidebar positions setting with CSS ?

Duplicate here http://drupal.org/node/1871680 because maybe both projects involved

I am using at-commerce http://drupal.org/project/at-commerce subtheme of AT.
Trying to theme sidebars depending on the theme setting "Choose sidebar positions" .../admin/appearance/settings/at_commerce left and right, stacked on the left, stacked on the right.

What is the best way to add image blur separators to sidebars and align it with CSS? The problem is to add images and put them correctly on the right or left position in the sidebars.
I am using body CSS classes suggestions "one-sidebar" and "two-sidebars" but there is no class to detect either sidebars left and right, stacked on the left or stacked on the right.
Guessing it mat be one of the page classes
page ssc-n ssw-n ssa-l sss-n btc-n btw-b bta-l bts-n ntc-n ntw-n nta-l nts-w ctc-n ctw-n cta-l cts-n ptc-n ptw-b pta-l pts-n
but cannot find documentation

Currently i am using this code:

.one-sidebar.sidebar-first .content-inner  {
background: url(images/blur-separator_sidebar_left.png) -5px top no-repeat;
padding-left: 25px;
}

.one-sidebar.sidebar-second #content-column .content-inner {
background: url(images/blur-separator_sidebar_left.png) right top no-repeat;
padding: 0 10px 0 0 ;
}

.two-sidebars .content-inner  {
background: url(images/blur-separator_sidebar_left.png) right top no-repeat;
padding-right: 10px;
}

.two-sidebars #content-column .content-inner  {
padding-left: 10px;
}

.two-sidebars .region-sidebar-first .region-inner  {
background: url(images/blur-separator_sidebar_left.png) right top no-repeat;

}

but it is not completely suite