Table header (e.g. university rankings) displays in front of support popup. #28225
Description
On the university rankings table (here), and I assume other tables done the same way, have the <thead> element displayed above the popup from the bottom of the page asking for financial support. The support popup has zindex set to 39, but the <th> elements within the <thead> have zindex set to 9999 via a .sticky class. I don't see that class defined in this repo so it might be custom for that specific page.
Here's a screenshot.
This is with Firefox on Linux