Guess — what you learn猜一猜 —— 你会学到什么
Six stations that only open after you have guessed. Nothing here sits still — least of all the answer. 六站，都要你先猜，才会打开。这里没有什么是静止的——答案尤其不是。
A fixed machine can be perfected. A moving one has to be designed for weather, wear, doors opening, laws changing — for everything it cannot control. 固定的机器可以被打磨到完美。移动的机器，必须为天气、磨损、每一次开门、每一次法规变动而设计——为它无法控制的一切而设计。
This is a training ground, not a lecture. Every station below asks its question first. Sit with it. Guess. Then open the panel, read the short note, and take the link to the full station — each one hands you on to the next. 这是一个训练场，不是讲座。下面的每一站都先抛出问题。先别急着找答案，猜一猜。然后展开面板，读一段短笔记，再顺着链接去完整的站点——每一站都会把你交给下一站。
You can walk it in order, or jump. The trail closes the loop either way. 你可以按顺序走，也可以跳着走。这条路线终究会合上。
How to walk it怎么走
Read the question on a station. Answer it in your head before you touch anything.读一站的问题。在碰任何东西之前，先在心里回答一遍。
Open the panel. A short note tells you what the station is actually holding.展开面板。一段短笔记告诉你，这一站真正装着什么。
Take the link to the full station, then come back and walk to the next one.顺着链接去完整的站点，再回来，走向下一站。
A fixed plant can be tuned around one climate, one grid, one schedule. Put the same machine on wheels and every assumption becomes a variable: load, road, weather, driver, the number of times a door is opened. The training begins here — designing for something that never sits still.固定的厂房可以围绕一种气候、一张电网、一份时刻表去调校。把同一台机器装上轮子，所有前提都变成了变量：载重、路况、天气、司机、门被打开的次数。训练从这里开始——为一个从不静止的东西做设计。
You learn你会学到How design assumptions behave the moment the ground moves.当地面开始移动，设计前提会如何一个个失效。
Not one journey — thousands. The same door opened ten thousand times, the same compressor cycling through a decade of summers. Repetition turns a small inefficiency into a large one, and a small choice into a whole footprint.不是一趟旅程，而是成千上万趟。同一扇门被打开一万次，同一台压缩机熬过十个夏天。重复把微小的损耗放大成巨大的代价，也把微小的选择放大成整体的足迹。
You learn你会学到Why duty cycles, not peak specs, decide real performance.为什么决定真实表现的是工况循环，而不是峰值参数。
Circularity is easy to say and hard to draw. Here it is taken apart point by point: materials, joints, the refrigerant charge, the panels that could come back and the ones that never will.循环容易说，难画。这一站把它一点一点拆开：材料、连接、制冷剂充注、哪些板材还能回来，哪些永远回不来。
You learn你会学到How to read a product as a set of returnable parts.如何把一件产品，读成一组可以归还的零件。
Somewhere under the cargo there is still a small engine burning. Map it — where the fuel goes, where the heat goes, where the emissions land — and an invisible cost turns into something you can design against.货物之下，往往还有一台小小的发动机在燃烧。把它画成图——燃料去了哪里、热去了哪里、排放落在哪里——看不见的成本，才变成可以对付的对象。
You learn你会学到How to trace combustion all the way through a cooling system.如何在一整套制冷系统里，追踪一次燃烧。
An emissions tier is written for an engine, but it travels — through the chassis, the depot, the route, the chilled rack in the shop, and finally the price on the label. Follow the standard the whole way and it stops being paperwork.排放阶段是为一台发动机写的，但它会一路旅行——穿过底盘、车队、路线、超市的冷柜，最后落在标签上的价格里。把标准一路跟到底，它就不再只是纸面文件。
You learn你会学到How one standard changes the shape of an entire supply chain.一个标准，如何改变整条供应链的形状。
Phase-downs, quotas, leak checks — read together, the F-Gas rules look less like a ban and more like a feedback loop, steering a whole industry by adjusting what is scarce. The last station asks you to design inside a control system instead of around it.配额削减、逐步淘汰、泄漏检查——放在一起读，F-Gas 规则更像一个反馈回路：通过调节「什么变得稀缺」，来操纵整个行业的方向。最后一站请你在控制系统内部做设计，而不是绕着它做设计。
You learn你会学到How policy works as feedback rather than prohibition.政策如何作为反馈运行，而不只是禁令。
Reference参考
Every station on the trail, with its full link — so nothing here is second-hand.路线上的每一站，附完整链接——这里没有二手转述。