Charts CSS Styling examples do not load and are outdated

Images do not load, both examples do not work as they are written, need small adjustments / improvements.

https://vaadin.com/docs/latest/components/charts/styling

<img width="799" height="1163" alt="Image" src="https://github.com/user-attachments/assets/42f9edb4-0ca3-4ef0-9bda-6ed15835ce2e" />