Okay, threw out the CSS and started from scratch with the stock CSS of the Strongly Typed template. Guess what? Carousel works at all resolutions under that. So now am selectively restoring chunks of the old custom CSS.
In retrospect, I wish I'd done that from the start, instead of trying to fix what was broken--this is turning out to be much easier & faster.
rproffitt commented: Similar to trying to touch up a bad paint job. It never looks right. +14