Xidorn Quan

There is a comprehensive explanation about why `:stuck` is not feasible in CSSWG's FAQ: https://wiki.csswg.org/faq#selectors-that-depend-on-layout

It seems people have been aware of the FAQ item. Sorry for the noise. For the proposal in the issue itself, the event approach, I don't think that's infeasible.

Thought about it a bit more, I guess even if we want something more convenient to get notified from stuck / unstuck, that's probably better also be an observer-like thing,...

On the other hand, it seems adding one observer type for each thing we want to listen to feels heavier than adding an event, where we can just share the...

I don't think it's worth adding them. Web content shouldn't use them. If we really want to take those tags into consideration, we really need a new mechanism to handle...

(For my own reference, filed [Gecko bug 1691243](https://bugzilla.mozilla.org/show_bug.cgi?id=1691243) for this change)

I had another look at the issue, and it seems to me that bopomofo does have justification opportunities inside, so removing `ruby-align: center` may not work for it. And I...

I don't think we want to change that behavior. It seems to me functions usually have special serialization rules, but not general property values.

It doesn't seem to me serialization of general specified value is defined anywhere... If we are trying to define it, it should match what engines are currently doing. My guess...

This should probably be defined in css-values spec I suppose.