Rendered diagrams overflow horizontally instead of scaling to container

[MrCoder]

Description

Rendered ZenUML diagrams wider than their container overflow horizontally instead of scaling down. This causes layout breakage or horizontal scrollbars when the diagram is embedded in narrow containers (e.g., Confluence macros, Markdown previews, or responsive web layouts).

Steps to Reproduce

1. Create a diagram that renders wider than the container (long participant names or many parallel messages).
2. Embed the rendered diagram inside a container that is narrower than the diagram width.
3. View the page.

Expected Behavior

The diagram scales down to fit within the container while maintaining readability.

Actual Behavior

The diagram maintains its full width and spills out of the container, forcing horizontal scrolling or breaking the surrounding layout.

Additional Context

Consider adding responsive sizing so diagrams respect the container width (e.g., applying max-width: 100% with an appropriate scaling strategy) or providing an option to auto-scale diagrams when they would otherwise overflow.