Credits

Icons from https://www.flaticon.com made by:

Freepik: https://www.freepik.com
PixelPerfect: https://www.flaticon.com/authors/pixel-perfect
Smashicons: https://www.flaticon.com/authors/smashicons
VectorsMarket https://www.flaticon.com/authors/vectorsmarket15

Pipes puzzle created by Gereleth https://github.com/gereleth (MIT License). Source code: https://github.com/gereleth/hexapipes