counterpoise

Drag a shape from the tray oto a hook, or tap a shape ad the a hook. Level every bar to fiish: weight × distace must match o both sides. Keys: arrows pick ad move, Eter hags, Z udo, R restart, H hit, Esc pause.

A hanging mobile, every bar tilted. Hang weighted shapes on its hooks and watch the whole mobile swing and settle into its new tilt. A bar hangs level when weight × distance matches on both sides, and everything hanging below a hook counts toward its weight. Nothing falls and nothing rushes you: the swing just shows your sum. On the bigger mobiles the trick is the order. Solve the bottom first, because those totals decide what the bars above them need.