[BUG] Desktop app 1.2581.0: <strong> in chat prose no longer renders bold — italic, inline code, and syntax-highlighted bold still work

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?

After updating to Claude Desktop 1.2581.0 (the April 14, 2026 desktop redesign release), bold text in Claude's chat responses no longer renders with any visual weight on macOS. The regression is very narrow and one observation pins it down:

| Context | Bold rendered? |
|---|---|
| **word** in chat prose (<strong>) | ❌ no — plain weight |
| **word** inside a ``` `markdown `` fenced block (via syntax highlighter) | ✅ yes |
| italic in chat prose (<em>) | ✅ yes |
| inline code | ✅ yes |
| Fenced code blocks generally | ✅ yes |
| bold-italic` in prose | ⚠️ italic applied, bold missing |

Bold works for the markdown-language syntax highlighter's token class but not for <strong> in chat prose. That tells us:

• The bold font weight is loaded and available.
• The renderer can apply font-weight: bold — just not in the prose path.
• This looks like a CSS regression in the redesigned chat-bubble stylesheet, not a parser, font, or encoding issue.

Reproduces in both the main chat view and inside Code-tab session transcripts. Not affected: the claude CLI in a real terminal, whose ANSI renderer still outputs bold correctly. So this is specifically an Electron GUI regression.

Nothing about markdown / typography changes is called out in the v1.2581.0 release notes or the April 14 desktop redesign blog post, so this appears unintentional.

What Should Happen?

**bold** and ***bold-italic*** in Claude's chat responses should render with bold weight in the message body, as they did before the April 14, 2026 desktop redesign and as they still do in the claude CLI terminal renderer.

Error Messages/Logs

No errors or logs — this is a visual CSS regression in the Electron app, not a crash or parse error.

Steps to Reproduce

1. Install / update to Claude Desktop 1.2581.0 on macOS (the April 14, 2026 redesign release).
2. Open the app and start a new chat.
3. Ask Claude: ` Reply with exactly: a **bold word**, an *italic word*, a ***bold-italic word***, and an inline code token. Then include those same four examples again inside a `markdown fenced code block`. `
4. Observe the rendered message.

Expected: bold, italic, bold-italic, and inline code all render with their styling in prose; inside the fenced block, the markdown syntax highlighter also styles them.

Actual: in prose, only italic and code render. **bold** and ***bold-italic*** come through at plain weight. Inside the fenced markdown code block, the same **word** does render bold (via syntax-highlighter token class). This mismatch between "bold works via highlighter token" and "bold does not work via <strong>" is the key diagnostic signal.

For comparison: the same prompt in the claude CLI (terminal) renders bold correctly, so the regression is specifically in the Electron GUI renderer.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Desktop app: the build immediately prior to 1.2581.0 (exact prior version unknown — updated 2026-04-14 when the app prompted me to update). Bold rendered correctly up to the April 14 redesign release.

Claude Code Version

2.1.19 (Claude Code) — CLI unaffected. Desktop app: 1.2581.0 (CFBundleShortVersionString).

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Environment

• Claude Desktop: 1.2581.0 (CFBundleShortVersionString from /Applications/Claude.app/Contents/Info.plist)
• Bundle ID: com.anthropic.claudefordesktop
• App bundle mtime: 2026-04-14 17:25 PDT (updated via the app's update prompt on the redesign release day)
• macOS: 15.7.3 (build 24G419)
• Arch: arm64 (Apple Silicon)
• Claude Code CLI: claude --version → 2.1.19 (Claude Code) — CLI terminal renderer is not affected.

Scope of this bug

This is specifically a Claude Desktop (Electron GUI) bug, not a CLI/terminal bug. The GitHub issue template has a "Terminal/Shell" field which I had to fill in to submit — that field is not meaningful for this report.

Suspected cause

Since bold renders for the markdown syntax-highlighter token class but not for <strong> in chat prose, the most likely culprits are:

• A redesigned chat-bubble stylesheet that broadly sets font-weight: inherit / font-weight: normal on message descendants and fails to re-assert bold for <strong> and <b>.
• A CSS reset / base layer in the new Electron bundle that strips user-agent font-weight: bold from semantic elements.
• Less likely: a font-stack change where the regular face is chosen even when weight 700 is requested in prose — unlikely because the same stack renders bold fine in the syntax-highlighter path.

Maintainers could confirm quickly by enabling DevTools on this Electron build (e.g. via --remote-debugging-port) and inspecting the computed font-weight on a <strong> element inside a rendered chat message.

Workaround

Drop into claude in a real terminal — its ANSI renderer is unaffected and still produces bold output correctly.

Screenshots

Attaching (a) a screenshot showing plain-weight **bold** in prose next to bold **word** inside a ``markdown fenced block within the same Claude Desktop reply, and (b) the same prompt's reply in the claude` CLI for comparison.

<img width="1067" height="880" alt="Image" src="https://github.com/user-attachments/assets/ec2e40e7-9c2d-4b21-9703-1d8a184fb60b" />