Add ALT+cursor navigation to node form
Tweak rendering

Boxes rounded and a little wider, background a little darker.
Tweak CSS, add font-stack

Adjust some sizes and padding, add a defined good-looking font stack for both
HTML and SVG content.
Separate connectors

Draw all connectors separately first to avoid any of them overlapping any
nodes.
Add Hotkey for delete (ALT+Delete)
Cleanup, add missing propTypes
Tweak nodes

Make them a little wider.
IDEA files