Zoho Wiki custom CSS scope, and base theme?

I have been testing the custom CSS feature, and am very encouraged to see that it can apply to any area of the page, not just the content.

To deploy this in earnest, a couple of things could use additional illumination:

1. For which pages type does zoho wiki include the customer-supplied CSS file? Yes for wiki pages obviously, and also for the Dashboard page, but not for Settings. Also Yes for the page editor, apparently.

Anyhow, rather than figuring this out by trial and error, could we have a list of the page types that get the CSS file, and what to look for in the CSS to positively distinguish them? (Example: Editor page has body#zw-editorContainer.)

2. Customer-supplied CSS relies on the underlying page structure and tags to remain stable over time. Which theme should we base the CSS upon in order to have least chance of future disruption?

Thanks!