Thread:Kirkburn/@comment-23930920-20180324140140/@comment-25024589-20180324145706

Due to the introduction of a new header style in 2017, the customization policy does not allow for site-wide customization of the page header, with the exception of two additions that are listed on the policy page. In personal CSS, however, you are permitted to do whatever you wish.

Hope this helps, and if you have additional questions, feel free to ask. :)