This thread is for showcasing interesting uses for and discussion of the template feature of Custom Header.
Since the template feature can render things like button & header text as HTML, you can do some interesting (but, entirely unintended) things.
This is an undocumented and mostly unsupported feature.
I’d like to keep the main thread for Custom Header clear of these discussions, giant screenshots, and huge codeblocks. This is now the place for such things. Thanks for understanding!