14
Firefox 144 has 2 new developer features (small but useful)
(programming.dev)
You can now jump to a CSS custom property's definition from within the var() function in style rules.
On clicking the arrow here:
You get jumped to where it's defined, and it's briefly highlighted.
The events tooltip in the Inspector now shows a badge besides custom events, making it easier to differentiate them from built-in events.
I think it's the "User-defined" badges I circled:
Features of the browser or features of the web platform?
Yes.