1980s children’s picture book I loved as a boy. It had wonderful, intricate illustrations of a miniature world (possibly in a tree?), where little humanoid creatures lived. I’m fairly certain there were certain sci-fi elements to it, and possibly some conflict between differently-colored factions. The illustrations included cutaways of tunnels and little cities etc. There may also have been bears with technology (rocket suits?), but that might be mixing up with another book. I’d love for someone to help – I’m a children’s book illustrator now and this was an early influence and inspiration for me.

Thank you!