Chrome side panel: Advanced settings popover overlaps the composer and causes horizontal scrolling

What version of the Codex App are you using (From “About Codex” dialog)?

26.805.11740

What subscription do you have?

ChatGPT Plus

What platform is your computer?

window x64

What issue are you seeing?

When Codex is used in a narrow Chrome side panel, opening the Advanced settings popover breaks the composer layout.

The popover overlaps the prompt input area instead of fitting within the available width or repositioning itself. A horizontal scrollbar also appears at the bottom of the composer, and some controls are crowded against or clipped by the right edge.

This makes the prompt input and its controls difficult to use in the normal side-panel layout.

The attached screenshot shows the issue with the UI language set to Korean.

What steps can reproduce the bug?

1. Open Codex in the Chrome extension side panel.
2. Resize the side panel to a relatively narrow width.
3. Open the model/reasoning control above the send button.
4. Open or display the Advanced settings popover.
5. Observe that the popover overlaps the composer and a horizontal scrollbar appears at the bottom of the input area.

The issue is visible in the attached screenshot.

What is the expected behavior?

The popover should remain fully visible within the side-panel viewport and should not overlap or expand the composer.

It should reposition, shrink, or switch to a mobile/narrow layout when there is insufficient horizontal space. The composer should not display a horizontal scrollbar, and all controls should remain accessible.

Additional information

Environment:

• Surface: Codex Chrome extension side panel
• UI language: Korean
• Window layout: Narrow side panel
• Screenshot attached

The problem appears to be related to responsive layout or popover positioning at narrow viewport widths.