I like this idea a lot! I think that there are a few small details that would improve the user experience if you're looking for feedback.
1. Please please please apply `user-select: none;` to everything within the circuit canvas. Almost more often than not I would end up dragging text that had been highlighted rather than any of the actual gates or inputs.
2. Having to switch between 'select', 'wire', and 'delete' modes is a bit cumbersome.
3. Absolutely no progress seems to be saved on navigation or page reload. I've completed the first level several times and if I go anywhere else or reload after completing it, the site shows zero levels completed and shows the tutorial again.
Thanks a lot! Will do!