[Bug] Code block highlighting renders as per-line ribbons instead of continuous rectangle on macOS

Bug Description
In the Claude Code extension in VS Code on macOS, code blocks paint as per-line ribbons. Fenced code blocks shade the inline code element, so multi-line blocks get line-by-line highlighter ribbons (ragged edges, gaps) instead of one continuous rectangle. Repro: ask for any multi-line code block. Fix: put the background on the block-level pre (transparent pre code), or display:block on the fenced code.

Environment Info

• Platform: darwin
• Terminal: vscode
• Version: 2.1.163
• Feedback ID: ac849bf2-45c3-4ffc-ad84-6a5f6a1106f1

Errors

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