I have been trying to get spoiler warnings like how they are on this page:
https://kiseki.fandom.com/wiki/Rean_Schwarzer
...to this one:
https://ceal.fandom.com/wiki/Crystal_Seal_Chronicle
Specifically, I would like to have a custom "this page contains spoilers"-box at the top of the page, and the spoilers hidden from view in a good way.
I think I've managed to get the spoilers to hide for now (though I'm open for suggestions for a better way, like a colapsible box that you can't acidentally view through hovering over it too long), but I have no idea how to add the box at the top like the Rean Schwarzer page has it. I've looked through the source code, but I simply have no idea what triggers this box there and how to replicate it.
Any suggestions?