Hide header, navbar and search (CSS)

[aisforandy]

Hi there! Thanks for making Plash!

I'm trying to find a way to use CSS to hide the header, navbar and search for https://lexica.art/

Bonus if it is possible to display a random image from Lexica as a full size image wallpaper!
Or any other AI art image galleries like https://legacy.midjourney.com/showcase/recent/ would be nice too!

Thank you!