I'm the admin of the Wolf's Rain wiki and I don't know if it ever had CSS added or if it got wiped? I've never dealt with this on any other wiki so I'm not sure what to do. Isn't there supposed to be some default CSS at the very least?
New wikis do not have any custom CSS by default, the key word here is 'custom' - the basics of making the Wiki load are already hardwired into Fandom. Take a read of this to get better understanding.
Given what Urere said and that there is no entry in the deletion log, that page almost certainly just hasn't been used yet. There is one way it may have existed and ended up like this; but that scenario is extremely unlikely.