I really like this. I hate doing layout in css.

I'm not sure if I missed it, but a few controls for the nodes would be cool (delete, swap with next, etc). I also couldn't focus the main node, after creating two nodes there. This was no problem, with the child nodes, because they shrink around the borders (which is amazing UX!).

Really cool project. Just curious, are you planning in open-sourcing it?