Hi Louis,
I visited the page you linked, but it looks like CommentBox is currently configured to allow comments from authenticated users only, so I’m not able to see the comment form as a guest.
Basic CommentBox styling can be configured through the CommentBox component options.
Some additional styling can also be applied using your template's custom CSS.
For more advanced customization, you will need to create a CommentBox layout override. This gives you full control over the styling without modifying the extension's core files.
You can find more information about where to place your custom CSS and overrides here:
https://www.firecoders.com/help-desk/commentbox/1468-where-to-store-user-css#p7258
I will also update the CommentBox documentation to make the available styling options and the recommended customization methods clearer.
If you let me know specifically which parts of CommentBox you are trying to change, I can also point you in the right direction.
Best regards,
Lefteris