2003734 - codepen.io - Target position at the anchor "end" is misplaced

Status: NEW

(Core :: CSS Parsing and Computation, defect)

Description

[Raul Bucata]

Attachment: Chr vs ff

Environment:
Operating system: Windows 10
Firefox version: Firefox 147.0a1 (2025-12-02)

Steps to reproduce:

1. Navigate to: https://codepen.io/jamessw/pen/pombqNj
2. Observe the Anchor and Target position in the code output

Expected Behavior:
The position of the Target is just below the Anchor

Actual Behavior:
The position of the Target is offset to the far right below the Anchor

Notes:

• Reproduces regardless of the status of ETP
• Issue found during the Anchor-positioning QA testing phase

Comment 1

[Emilio Cobos Álvarez [:emilio]]

This seems very similar to some of the other real site bugs. It seems we should shrink-wrap. Jonathan you've worked on position area, is this on your radar?

Comment 2

[David Shin[:dshin]]

Given the positioning, this is likely bug 1989292 - We use the available CB size of the scrollport so the positioning grid has the height 0.
(FWIW, the sizing is wrong as well even if .make-me-scroll is decreased, and that is indeed bug 1991929)