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.
url).type values for future rules; recommend usage of .constructor.name (Issue #4142: Can we start ignoring CSSRule.type?)visibility:hidden with visible descendants for overflow:scroll to behave the same as overflow:hidden (Issue #4113: Should a visibility:hidden overflow:scroll be scrollable?)