That's my problem. "modal dialog" is a SCREEN concept that means nothing in any other type of UA. The very concept of it being a "modal dialog" is gibberish confusing nonsense outside that ONE media! Like my braille reader.

The reason to trap focus is that it's basically taking over the viewport, something it would NOT do -- and probably shouldn't do -- for non-screen behaviors.

That behavior you keep describing means -- and should mean -- NOTHING on any other media target.

Also I have yet to see that "it seizes focus" behavior actually work. It does for tabbing, but anchors and buttons still sort upwards so... you're still coding a ton of extra crap.

at least in Firefox, Edge, and Vivaldi. It still doesn't "do" that properly. I've not tested latest chrome, but since that usually lags BEHIND Vivaldi and sometimes even edge on Chromium features...