Fun share - c0ffee anyone? hexadecimal conversions (recursive)

i don’t know if hexadecimals are still being used - now in this age of nocode!
anyway, i would like to share my hexadecimal conversion “app”

here are the blocks used (only 4!)

both conversion functions are written in recursive form - ie. the definition of the function incudes itself! (hence there are no loops!)
here’s the project link: