For everyone looking for a new way to get a compact mode, kiosk mode, hiding header, etc. Along with many other things, card-mod can do that.
Check out the wiki’s theme cookbook. It’s recently been updated since I archived CH and more things keep being added. Almost everything that CH could do card-mod can do for you, with a bit of extra work. Configs are easily shared so be sure to check out what folks are doing with it.