css.at-rules.page - margin at-rules and margin at-rule styles compatibility is missing

[ArianeBouchardConformit]

What type of issue is this?

Missing compatibility data

What information was incorrect, unhelpful, or incomplete?

Most of the possibilities offered by @page and its sub-at-rules are not supported by any browser yet. A warning box says this in the content, but a quick look at the compatibility table seems to say everything is supported.

What browsers does this problem apply to, if applicable?

Chromium (Chrome, Edge 79+, Opera, Samsung Internet), Firefox, Legacy Edge (12-18), Safari

What did you expect to see?

Considering you can't do much with @page right now, I think it'd be important to add rows to the table that show that at-rules such as @bottom-left are not supported anywhere yet.

OR there could be a separate page for each at-rule that lists every possible CSS rule for the at-rule and what supports it. It'd be all "No" for now, though, of course.

Did you test this? If so, how?

Tried to do something like this

@page {
   @bottom-right {
      content: "!!Page " counter(page) " of " counter(pages);
   }
   @bottom-left-corner {
      content: "!!Page " counter(page) " of " counter(pages);
   }

   @bottom-left {
      content: "!!Page " counter(page) " of " counter(pages);
   }

   @left-bottom {
      content: "!!Page " counter(page) " of " counter(pages);
   }

   @bottom-center {
      content: "!!Page " counter(page) " of " counter(pages);
   }
}

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

No response

Do you have anything more you want to share?

No response

MDN URL

https://developer.mozilla.org/en-US/docs/Web/CSS/@page

MDN metadata

MDN page report details

• Query: css.at-rules.page
• Report started: 2023-11-30T16:55:17.810Z