I tried both: added multiple variations of z-index: and background-color:. There must have been something else in there neutering these. I didn't see it in th

I tried both: added multiple variations of z-index: and background-color:. There must have been something else in there neutering these. I didn't see it in the developer console. Now you all must be right: This must have been fixable somehow. Now the application contains 10+ years of CSS evolution, maintained by at least 4 predecessors and a bunch of quick and dirty maintenance hacks. It's a huge tower of exceptions built on exceptions . I had already blow way past my time budget for something I had estimated easy, and creating a table wasn't even the core of the job. So I cut my losses.