Dropdown lists under Settings popup don't expand due to CSS mis-interaction. #8290

In Etherpad 3.3.4 (and presumably on the develop branch right now, because the relevant CSS is the same, but I haven't tested this on latest develop):

Dropdown lists in the Settings popup (such as the "Font type" dropdown or the "Language" dropdown) don't drop down to show all their items. When you click on them, the little expand/contract triangle rotates, but the actual dropdown menu does not appear. The following two screenshots show this.

First, this is what it looks like when the bug is present -- notice how the triangle for the right-side "Language" dropdown (that is, the one under Pad-wide Settings) is rotated to point up -- I have actually clicked on that dropdown to try to open it, but no menu appeared underneath, and the only option showing is the default choice "English":

Now, with the bug fixed (with a PR I'll file momentarily, that touches one line in src/static/skins/colibris/src/components/popup.css), I see what I expected to see:

Server:

• Etherpad version: 3.3.4
• OS: Debian GNU/Linux 13 (Trixie)
• Node.js version: 24.18.0
• npm version: 11.16.0
• Is the server free of plugins: No. The following plugins are installed: ep_etherpad-lite 3.3.6, ep_hash_auth 11.0.25, ep_hyperlinked_text 0.2.7, and ep_print 11.0.28.
• Are you using any abstraction IE docker? No.

Desktop:

• OS: Debian testing, dist-updated within the last day or so.
• Browser: Firefox 140.16.0esr (64-bit), and Chromium 154.0.8037.57 (Official Build) built on Debian GNU/Linux forky/sid (x86_64)
• Version: see above

Additional context

I have a tentative fix for this bug, and will file an associated PR in a moment. I believe the root cause of the problem is an unfortunate interaction between PR #4137 (fixes issue #4136) and PR #7703 (fixes issue #7696). The former added a prefers-reduced-motion check to a few places in the Colibris skin, including the popup CSS; the latter made the Settings popup scrollable in all display environments. (I'm not an expert in these things, so I -- or rather, Claude Code and I -- may have mis-diagnosed.)

This change fixes the problem for me:

--- src/static/skins/colibris/src/components/ORIG-popup.css       2026-09-29 19:37:56.436952929 +0000
+++ src/static/skins/colibris/src/components/popup.css   2026-09-29 20:31:54.554765556 +0000
@@ -72,7 +72,7 @@
 
 @media (prefers-reduced-motion) {
   .popup>.popup-content {
-    transform: scale(1);
+    transform: none;
     transition: none;
   }
   .nice-select .list {

I'll try to get a proper PR filed right away.