Mermaid erDiagram attributes are unreadable in dark mode

[kuuumo]

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

26.506.31421 (CFBundleVersion 2620)

What subscription do you have?

Pro

What platform is your computer?

Darwin 25.4.0 arm64 arm

What issue are you seeing?

In the Codex App Mermaid preview, erDiagram tables can render with near-white text on white attribute rows when Codex is used in a dark UI. This makes some entity attributes effectively unreadable.

The screenshot I have is sanitized and uses only sample entities (ACCOUNT, PROJECT, ACCOUNT_PROJECT, PROJECT_RULE). The affected rows show white or near-white attribute text on white table cells.

Relationship labels are also low contrast in the dark UI.

What steps can reproduce the bug?

Paste the following Mermaid diagram into Codex while using the dark UI:

erDiagram
  ACCOUNT ||--o{ ACCOUNT_PROJECT : has
  PROJECT ||--o{ ACCOUNT_PROJECT : assigned_to
  PROJECT ||--o{ PROJECT_RULE : has_rules

  ACCOUNT {
    string id
    string name
    string email
    int status
  }

  PROJECT {
    string id
    string name
    string description
    boolean active
  }

  ACCOUNT_PROJECT {
    string id
    string account_id
    string project_id
  }

  PROJECT_RULE {
    string id
    string project_id
    string rule_name
  }

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Observed result: fields such as id, email, description, and project_id are difficult or impossible to read on the white rows.

Changing Mermaid themes did not resolve it reliably.

What is the expected behavior?

All table attribute text should remain readable in dark mode. If attribute rows use a white or light background, their text should use a dark foreground color.

Additional information

This looks similar to Mermaid dark-mode embedding issues reported in other environments, especially ER diagrams where some cells appear to keep light-theme styling while inheriting dark-theme text colors.

Related discussions:

• https://forum.obsidian.md/t/mermaid-er-diagram-uses-certain-light-mode-elements-in-the-default-dark-theme/67557
• https://forum.obsidian.md/t/some-mermaid-components-dont-respect-dark-mode/82547
• https://github.com/orgs/community/discussions/35733