[BUG] Blank space on the left of conversations in Claude Mac Desktop app

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?

Hello Anthropic team,

I'm experiencing a visual bug on the Claude desktop app for macOS.

Issue: A white horizontal band appears across the middle of the interface, but only when a conversation is open. The app displays correctly on the home screen and in Settings.
If I put the app in full screen mode it's okay, but if not in full screen it's like the white space on the left of the conversations just doesn't resize and have an bigger z-index than the text.

Environment:

• macOS, Retina display
• Latest version of Claude desktop app (freshly reinstalled)

What I've already tried:

• Restarting the app
• Resizing the window
• Clearing the cache (~/Library/Application Support/Claude/Cache)
• Full uninstall and reinstall

None of these resolved the issue. The band is fixed (doesn't move with scroll) and appears consistently on every conversation opened.

I've attached a screenshot for reference.

Please let me know if you need additional information (logs, app version, macOS version).

What Should Happen?

normal display

<img width="709" height="488" alt="Image" src="https://github.com/user-attachments/assets/952f29ba-7838-4ca9-a9db-c1b09f9644d3" />

Error Messages/Logs

Steps to Reproduce

Steps to reproduce:

1. Open Claude desktop app → displays correctly
2. Open any conversation → white horizontal band appears across the interface

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.3109.0 (35cbf6)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_