nuclear radiation 2

This update significantly revised the content of the fourth stage of the technology tree, as well as a small portion of content in other stages. During the process, some interesting things happened—I forgot my account password, went through a search, and even created a new repository before finally finding it.

本次更新大幅修改了科技线第四阶段的内容，以及少部分其他阶段的内容，期间发生了一些趣事，我忘记账号了，一番找寻，甚至新建了一个仓库，终于给我找找了