Movable Type css with subdomains

Update: I spoke too soon. My initial fix did not work (see strike below. The fix that actually worked for me follows. –elb 2012-09-17 12:21:24
Adding subdomains to my new Movable Type 5 website screwed up the links to my css stylesheets.
The fix is easy and I think it will hold up over template changes and updates, but as an MT newbie it took me a while to track down.
First, my setup here on my site looks something like this:
In the template governing the html head, the links to the stylesheets were pointing to the relative domain. This worked fine at the root level,, but broke when it moved to a subdomain (blog., and linked.).

Updating the styles.css at the root level seemed to fix my formatting problem. I changed from this:
@import url(/mt-static/themes-base/blog.css);
@import url(/mt-static/support/themes/professional-blue/professional-blue.css);
…to this:
@import url(;
@import url(;

OK, I got it. I was on the right track but in the wrong place. It ended up being a huge MT rookie oversight that was quickly repaired by updating mt-config.cgi with urls instead of relative directory paths. Now, it looks like this:
…and so far so good. I’ll let you know if I find anything else.