Mermaid also works in Org content. Use a source block whose language is mermaid; the theme converts Hugo's highlighted Org output before rendering the diagram.

Release states

State diagrams can summarize a workflow without maintaining a separate image:

stateDiagram-v2
    [*] --> Draft
    Draft --> Review: Open pull request
    Review --> Draft: Request changes
    Review --> Published: Approve and merge
    Published --> [*]

Content model

Entity relationship diagrams are useful for describing structured content:

erDiagram
    AUTHOR ||--o{ POST : writes
    POST }o--o{ TAG : uses
    AUTHOR {
        string name
        string email
    }
    POST {
        string title
        date published
    }
    TAG {
        string name
    }

Like the Markdown examples, these diagrams use the site's active palette and hand-drawn style, and are re-rendered when the light or dark theme changes.