This is a page from the Cascading Style Sheets Working Group Blog. Some other places to find information are the “current work” page, the www-style mailing list, the Future of CSS syndicator, and the issue list on Github.
Do you want to know how the CSS WG works? Fantasai has written about:csswg, An Inside View of the CSS Working Group at W3C.
media_list
production so that Media Queries can easily swap out the relevant part of CSS2.1’s syntax.@media { ... }
(no media type or query) is invalid.border-image
and box-shadow
not affecting layout or triggering scrolling, and the CSS3 module covering overflow will need to discuss in detail the differences between overflow that affects layout/scrolling, and overflow that does not.