:scope pseudo-class for the Selectors API
Please implement the :scope pseudo-class to refer to the context in querySelector(All). You’re the last browser remaining 
The :scope pseudo-class is now on the Microsoft Edge backlog with a priority of medium. You can track status changes at https://dev.modern.ie/platform/status/csscontextualreferenceelementpseudoclassscope/
Brian Staruk commented
This feature was first noted almost 4 years ago, and it's still not supported in Edge.
Just when I thought I was done with my app (developed in Chrome, but supposed to run in win 10 universal app), I find that :scope is not impl yet. Any closer to that backlog entry?
Andy Fuchs commented