Board Thread:Support Requests - Designing Your Wiki/@comment-26577241-20180708014404/@comment-27345308-20180708171556

Are you trying ? Because there is no  CSS property, and the   HTML attribute is being deprecated. You should center your elements using combinations of  on the parent and   on the children (if I recall correctly).

Aside from that, I think it would have been much better if you started a separate forum topic about this, as it isn't directly related to the question and wiki presented in the OP.