Allow Mermaid Diagrams To Be Expanded or Viewed Full-Screen

What version of the Codex App are you using (From “About Codex” dialog)?

Version 260205.1301

What subscription do you have?

Plus

What issue are you seeing?

<img width="780" height="254" alt="Image" src="https://github.com/user-attachments/assets/7edbf92e-8380-4517-ae90-43d69f44f1b8" />

What issue are you seeing?

Mermaid diagrams rendered in issues/PRs cannot be viewed in full screen or expanded, which makes larger diagrams difficult or impossible to read. Complex diagrams get compressed into small containers and become hard to navigate.

Additional information

Large architecture, workflow, or agent diagrams become difficult to use without zoom or full-screen support. This particularly affects complex system and agent workflows where readability is critical.

What steps can reproduce the bug?

What steps can reproduce the bug?

1. Create or view a Mermaid diagram in an issue, PR, or documentation page.
2. Render a medium or large diagram.
3. Attempt to expand or view the diagram in full screen.
4. Notice there is no option to enlarge or full-screen the diagram.

What is the expected behavior?

What is the expected behavior?

Mermaid diagrams should have an option to open in full-screen or expanded view so users can properly read and navigate larger diagrams.

Expected improvements could include:

• Full-screen or expand button for diagrams
• Click-to-zoom or modal expansion
• Pan and zoom controls
• Ability to download or open diagram in a separate view

Additional information

Additional information

Large architecture, workflow, or agent diagrams become difficult to use without zoom or full-screen support. This particularly affects complex system and agent workflows where readability is critical.