Bartik block styling tied to classes that also control layout

In Panels Everywhere, I'm working on a system that doesn't use the normal layout, since I replace page.tpl.php with a Panels layout.

I do, however, want (where possible) to retain things like block styling.

In Bartik, block styling depends upon what type of region it's in; i.e, the sidebar, triptych or whatever. However, the actual class used for this also controls layout. i.e,

.block .sidebar {
  // block styling information here
}

The problem is that when not using Bartik's basic layout, I cannot access this style. The sidebar class comes with a width which then tries to apply to whatever region I put that in.

I'm not sure exactly the best way to deal with this, but it would be great (for me) if either the .sidebar class did not include the width or if some other class was used on sidebars to indicate styling. I like sidebar a lot because it's a generic class that's easy to apply, so it would be nicest if the layout information were applied to the more specific type of sidebar.