Double-click empty space: new node
Space: child Tab: sibling Shift+Tab: parent
Enter: edit text (Enter again to commit)
Arrows / WASD: jump to nearest node Q: auto-fit node width
C: color picker — ← → to choose, Enter to apply (or 1-7)
H: collapse / expand subtree V: toggle yellow / gray
Right-click node: color / delete
Backspace: delete ⌘Z: undo ⌘⇧Z: redo
Z / X: zoom out / in Scroll: zoom Drag empty canvas: pan