Really nice visuals!

Could you give a little more information about the 'stack' you're using to display the clock?

From this:

> This minicomputer will power the clock. The Pi 3B+ seems just enough to render some simple animations.

> I also tried with a Raspberry Pi Zero 2, but 512 MB of RAM were too little to run a modern browser, sadly. I think a Pi 4 might be a good sweet spot between processing power and price, currently.

...are you essentially displaying a full-screen browser window in the default Raspbian window manager and then running local Javascript for the clock itself?