Well, I did it! I successfully created a subtheme for Drupal, and it showed up in the administrative manager and everything! I haven't tweaked it yet - only on paper so far (I'm marking up the main theme's CSS with notes and stuff - I can't help it, sometimes I need paper and pencil), but I'll be trying that first thing tomorrow (after brewing some coffee, that is).
My plan for the coming weeks is to spend half the day on the EDMS (today I managed to create a batch file that actually works [after a couple of tries; gotta have those quotes in the right place!] to do all the "mkdir" commands to recreate the new, collapsed structure) and half on Drupal (see above). So far so good! Well, except for yesterday - my plan to work on Drupal in the afternoon was sidelined by a not-very-enjoyable vasovagal reaction to the hyalgen injections. (Yes, I passed out. A short-lived but exciting time was had by my husband and the orthopedist.) If it weren't for the fact that the last round worked so well for me... dang it. Ah well; it's the price you pay for having knees forty years older than you are.
Currently 92° and cloudy; it feels cooler than that, but the mugginess is not pleasant. How do folks on the East Coast live with this year-round?