[Cowork] Sidebar panel overlaps chat area and obscures message input box

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?

When the Cowork sidebar panel is opened, it renders as a floating overlay on top of the main conversation area instead of docking alongside the content. This causes two problems: (1) the left portion of conversation text is hidden behind the panel — responses appear mid-sentence — and (2) the white message input box is partially or fully obscured, making it impossible to type without first closing the panel every time.

Steps to reproduce:

1. Open Claude desktop app in Cowork mode
2. Click the Cowork button to open the sidebar panel
3. Panel overlays the chat area — text cut off on the left, input box obscured

Expected: sidebar docks alongside content, or floats without covering the input box
Actual: panel renders as a floating layer over the conversation

Claude desktop: 1.4758.0 (fb266c) — built 2026-04-24
macOS: Tahoe 26.3.1(a)
Display: standard, no custom scaling

<img width="2600" height="1621" alt="Image" src="https://github.com/user-attachments/assets/aa2db015-bd8c-43a7-83c3-f537dde29f98" />

What Should Happen?

Identify why and fix it.

Error Messages/Logs

Steps to Reproduce

It happens any time that I shrink the screen down so that the sidebar overlaps.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude 1.4758.0 (fb266c) 2026-04-24T20:22:30.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_