[BUG] Chat panel squeezed between left sidebar and right panel after recent update — text cut off on both sides

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

After a recent Cowork update, the chat panel layout is broken. The chat text is being cut off on the left side — the panel appears squeezed between the left navigation sidebar and the right Progress/Working Folders panel. The chat content is only partially visible and text is clipped on both edges. Restarting the app, relaunching, and resizing the window do not resolve the issue. This did not occur before the update. Screenshots attached.

<img width="1284" height="1018" alt="Image" src="https://github.com/user-attachments/assets/8fa468e3-bf35-4406-85c6-074d1f9aea3b" />

What Should Happen?

The chat panel should display full-width text centered between the left sidebar and right panel, with no content clipped or cut off on either side. All previous versions of Cowork displayed the chat correctly in this layout.

Error Messages/Logs

Steps to Reproduce

Open Cowork desktop app
Start or continue any conversation
Observe that the chat panel text is cut off on the left side
The panel appears squeezed between the left navigation sidebar and the right Progress/Working Folders panel
Resizing the window does not fix the issue
Closing and relaunching the app does not fix the issue
Restarting the computer does not fix the issue

Note: This issue began after the most recent Cowork update. No configuration changes were made by the user.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Unknown — the layout worked correctly prior to the most recent automatic update. Current version can be found in the app

Claude Code Version

claude --version

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

<img width="1285" height="1028" alt="Image" src="https://github.com/user-attachments/assets/c9ec905f-5110-478b-a326-93e58e5d192d" />