Action 1387: CSS Borders and Backgrounds review

https://www.w3.org/WAI/PF/Group/track/actions/1387

I've reviewed this spec, and it's not bad.  I have some minor concerns/ideas.  Does this look reasonable to send to the CSS working group as feedback?

There is a note about not using css background-image for accessibility reasons, which is well-written and gives the correct advice based on current technology.  However, due to performance impacts, many web developers will not be willing to switch to using <img> elements instead of background-image for all important graphics.  I would like to understand the status of work to make a high contrast media query a w3c spec.  Does this fall under CSS?  If not, where would it fall?  IE has a vendor-prefixed one, which we've been using with good results in Windows 8 apps and Microsoft websites.  http://msdn.microsoft.com/en-us/library/windows/apps/hh466205.aspx

My other question is about drawing focus rings.  I know this can be done with existing border properties and the :focus psudoclass, which is good.  It would be nice to have some discussion of this in the spec and an example.  A WCAG technique would also be good (there may be one).

It would also be interesting to look at whether a focus ring is a different type of border, that should be drawn in a different position or style by default, and how CSS based focus indicators interact with browser and OS focus indicators.  This is a feature request, and could wait until the next version.

I've marked the issue pending review and will close it once we've agreed on feedback to send to CSS.