User blog comment:Rappy 4187/Technical Update: November 23, 2016/@comment-26279466-20161124105515/@comment-26402117-20161129122848

I think individual JS syntax errors or conflicts actually break the Discussions interface and just shows the spinner, because it operates on a JS framework. I found that out the hard way by not excluding Discussions in Tampermonkey scripts (which I use because toggling personal scripts is so convenient).

CSS would touch on what Fandom wants Discussions to look like and what it wants users to see. The TOU and the customization policy come to mind, seeing as they set the bar for wikis to make the skin their own. Even without CSS, Discussions could take further cues for the color scheme (like making the link color a higher-contrast shade of the header color).