鲁布·戈德堡连锁机关

Create an animated interactive Rube Goldberg machine in the browser.

The machine must contain at least eight distinct stages forming one continuous causal chain.

The user should be able to:
- start the machine
- pause it
- resume it
- reset it
- step through the simulation slowly

Each stage must visibly cause the next stage rather than merely playing on a fixed independent timer.

Make the result visually polished and satisfying to watch.