This is a heavily interactive web application, and JavaScript is required. Simple HTML interfaces are possible, but that is not what this is.
Post
Azeria
aze.azeria.dev
did:plc:c2ls3lbepsxajz4lx3wdxcu7
I got to the same point you did in the image (dark blue).
Then, I noticed that the top central block had only two possible configurations: with either the 9 or the 4 on the top left of that block (F-1 square).
With that, I decided to solve both ways. Only with the 9 I got it right 😄
2026-04-22T13:19:35.857Z