Rube Goldberg Machine

Original prompt

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.

Chinese translation

在浏览器中创建一个可交互的鲁布·戈德堡连锁机关。整个装置至少包含八个彼此不同的阶段，并形成一条连续的因果链。用户应能够启动、暂停、继续、重置，并以慢速或逐步方式观察模拟。每个阶段必须由前一阶段的实际状态触发，而不是依靠相互独立的固定时间定时器播放。整体视觉应精致，并具有令人满意的连续运动感。

Expected outcome

The deliverable should be a state- or event-driven chain-reaction simulation rather than a sequence of unrelated timed animations. Each stage should visibly trigger the next through a causal transition. Pause and step controls should operate on one coherent simulation clock, and reset should fully restore the initial state.

Additional verification guidance

• Pause at arbitrary stages and confirm later stages do not continue independently; each stage should start only after its preceding trigger condition is satisfied.
• Use step or slow-motion mode to inspect the chain and verify at least eight distinct, visibly causal stages.
• Reset and rerun multiple times to confirm repeatability, no stale state, no premature triggers, and no permanent deadlocks.
• Verify that the machine remains usable, complete, and synchronized across different viewport sizes and frame rates.