Last user message overlays content when scrolling chat history

Description

When scrolling up in the chat history, the most recently sent user message renders as a sticky/floating overlay that covers the entire content area, making it impossible to read prior messages or assistant responses underneath.

The overlay does not dismiss when scrolling — it stays pinned in front of the conversation, blocking the view of any content below it (assistant responses, files in the right panel, command input area, etc.).

Repro

1. Open Claude Code desktop app, start a chat session
2. Send a multi-line user message (text + optional screenshot/image upload)
3. Wait for the assistant to respond fully
4. Send another message
5. Scroll up to review earlier content in the conversation

Result: The last user message stays \"stuck\" covering most of the viewport, layered on top of the chat content and any side panels. The overlay blocks reading of:

• Previous assistant responses
• Right-side file/document panels
• Bottom command input area

Expected behavior

User messages should scroll out of view normally with the rest of the conversation history. Nothing should be pinned/floating over the chat or adjacent panels.

Workaround

None known. The user has to manually dismiss/clear the overlay (sometimes scrolling to bottom then back up helps, sometimes not). Closing and reopening the chat sometimes works.

Environment

• OS: macOS 26.4 (Darwin Kernel 25.4.0, arm64 / Apple Silicon — MacBook Air)
• Claude Code version: 2.1.141
• Interface: Claude Code desktop app
• Model: Opus 4.7 (1M context)
• Plugins/MCP active: context7, playwright, supabase, ccd-session

Reporter notes

Reported by an active UX designer using Claude Code for design system work. Triggers consistently when sending long messages with image uploads in sessions that have substantial scrollback. Screenshots can be attached after submission (cannot upload via CLI).

<img width="2000" height="1564" alt="Image" src="https://github.com/user-attachments/assets/c8449e12-257e-4338-a156-3f19956da500" />