[BUG] Code block font size reduced in Claude Desktop v1.2581.0

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?

Version: 1.2581.0 (f10398) 2026-04-14
What's wrong: Code block text is smaller than previous builds; chat and Cowork body text unaffected
OS: macOS
Reproduction: Open any chat, ask for a code response, observe reduced font size vs prior version

What Should Happen?

allow font size change in settings or revert back to prevous version of code.

Error Messages/Logs

Steps to Reproduce

Version: 1.2581.0 (f10398) 2026-04-14
What's wrong: Code block text is smaller than previous builds; chat and Cowork body text unaffected
OS: macOS / Windows (whichever applies)
Reproduction: Open any chat, ask for a code response, observe reduced font size vs prior version

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.2581.0 (f10398) 2026-04-14

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_