[BUG]

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?

Summary

After a recent update, Claude for Desktop (macOS) has a layout bug where
the chat content area's left edge is hidden underneath the sidebar when
the sidebar is expanded.

Environment

• OS: macOS (Darwin 24.6.0)
• App: Claude for Desktop
• Bundle ID: com.anthropic.claudefordesktop
• Version: 1.2581.0
• Display setup: Built-in Retina display + external display (DELL S2421HS)

Symptoms

1. With the sidebar expanded, the chat content area's left margin does not

account for the sidebar width, causing content to render beneath the sidebar

1. As a result, the left portion of every line of text is clipped and unreadable

(e.g., "Fix display layout for full screen" appears as "ayout for full screen")

1. Switching to full-screen mode does not restore the layout; the visible

content area actually shrinks further

1. None of the following resolved the issue: window resize, sidebar toggle,

app restart, or defaults delete com.anthropic.claudefordesktop

Steps to Reproduce

1. Launch Claude for Desktop (v1.2581.0)
2. Expand the sidebar
3. Open any session

→ Chat content renders with its left edge hidden under the sidebar

Expected Behavior

Chat content should not overlap the sidebar; its left margin should
correctly reserve space equal to the sidebar's width.

Actual Behavior

The left edge of the chat content is clipped underneath the sidebar,
hiding the first several characters of every line.

Workarounds Attempted

• [x] Toggling the sidebar open/close — no effect
• [x] Resizing the window — no effect
• [x] Switching to full-screen mode — no effect (made it worse)
• [x] Quitting and relaunching the app — no effect
• [x] Resetting preferences via defaults delete com.anthropic.claudefordesktop — no effect

Screenshots

[Attached]

Additional Context

This bug started appearing after updating to v1.2581.0. The display
rendered correctly prior to the update.

<img width="1296" height="856" alt="Image" src="https://github.com/user-attachments/assets/83d21412-64f9-41ff-8082-cba892d3e9ec" />

What Should Happen?

The chat content area should not overlap with the sidebar. When the sidebar
is expanded, the chat content's left margin should correctly reserve space
equal to the sidebar's width, so that all text is fully visible and no
characters are clipped on the left edge.

Additionally, switching to full-screen mode should display the content
properly without further shrinking the visible area.

Error Messages/Logs

Steps to Reproduce

1. Update Claude for Desktop to version 1.2581.0 on macOS
2. Launch the Claude app
3. Make sure the sidebar is expanded (showing sessions list)
4. Open any existing chat session, or start a new one
5. Observe the chat content area

Result: The left edge of every line of chat text is hidden underneath the
sidebar. The first several characters of each line are clipped and unreadable.

Additional reproduction note:

• Toggling full-screen mode does not fix the issue; instead, the visible

content area shrinks further.

• The issue persists after quitting and relaunching the app, resizing the

window, and resetting preferences with defaults delete com.anthropic.claudefordesktop.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.2581.0　クロードコード

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_