Stuff Seems To Disappear.

Partly for the devel team — Jason, in particular — partly for you.

Yes, this is the kind of story that starts by quoting the W3C’s CSS 2.1 Specification on how to apply style rules to web pages.

6.4 The cascade

Style sheets may have three different origins: author, user, and user agent [the web browser]. […]

Style sheets from these three origins will overlap in scope, and they interact according to the cascade.

The CSS cascade assigns a weight to each style rule. When several rules apply, the one with the greatest weight takes precedence.

By default, rules in author style sheets have more weight than rules in user style sheets. Precedence is reversed, however, for “!important” rules. All user and author rules have more weight than rules in the UA’s default style sheet.

Yes ?

This text is a small-picture look at one of the grand underpinning ideas of the web. Every web page is a democracy of three parties: the author, the user, and the web browser. Each gets to contribute to the overall style of the page. And a set of laws decides how those contributions collaborate and merge, to get us to the web page you see on your screen.

Yes. And for the whole story, in their words, follow the link to Medium.