Board Thread:Support Requests - Designing Your Wiki/@comment-4432509-20200623114555/@comment-26611127-20200625025633

The is the default CSS of the triangles. You can change it to your preferred styling.

I would highly suggest learning how to retrieve CSS classes, because constantly asking for each specific class that you want to customize will ultimately be to your detriment. In my opinion it's an easy thing to pick up and learn, and has many uses outside of Fandom.