Modify "You need to log in to see that topic." screen

Is there an easy way to modify the message/screen that displays when a user lands on the “You need to log in to see that topic.” screen? Is this page templated at all? I’d like to add additional information.

I know I can change the raw text, but what about adding graphics, links, more content?

/admin/customize/text content and search for “you need to log in”


Is there any way to use HTML or include links? HTML renders as text.

Not at this time, no.

Is there any good way to try to go about modifying this or hacking it to be able to add rich content?