Summary

Firefox 145 adds support for the position-area property: see https://bugzilla.mozilla.org/show_bug.cgi?id=1924086. From testing, it appears to be only enabled in nightly builds.

This PR therefore updates the position-area Fx data to "preview".

I also noticed that a couple of value names have recently changed:

• span-x-self-start -> span-self-x-start
• span-x-self-end -> span-self-x-end
• span-y-self-end -> span-self-y-end
• span-y-self-start -> span-self-y-start
• x-self-end -> self-x-end
• x-self-start -> self-x-start
• y-self-end -> self-y-end
• y-self-start -> self-y-start

I took this opportunity to:

• Update these values and their spec URLs.
• Update the Safari support data for these values to say that it supports them with an alternative name (I tested them in Safari 26, and it still supports them with the original names)
• Update the Chrome support data for these values to say that it supports them with an alternative name up until 143, and supports them with the correct name from 143 onwards (I tested them in multiple Chrome versions, and this still appears to be the case.)

Test results and supporting details

Related issues