Re: Two proposals: 1. Implement a new pseudo-class selector ::between, 2. Allow pseudo-class selectors to be recursive

Some years ago I proposed the same idea in https://lists.w3.org/Archives/Public/www-style/2015Oct/0105.html

I have been refining it in https://github.com/Loirooriol/css-contents

As Daniel says, these new boxes shouldn't be inserted by default. An UA-origin `display: contents` can be used to address this.

Then the main problem is inheritance. It would be nice to set e.g. `color` in this pseudo-element, and let the children of the element inherit it.

But using the `inherit` keyword on a non-inherited property should continue getting the value from the parent element and not from the pseudo-element, which will probably have the initial value (unless `all: inherit` is added in UA origin).

I have filed https://github.com/w3c/csswg-drafts/issues/2406 if you want to discuss in github.

--Oriol