'Extend license' button produces a considerably weird effect

[LinuxOnTheDesktop]

I think that the 'extend license' button has a very weird effect. To wit: when Thunderbird is set to use system (dark) mode, or dark mode, or light mode, there is a confusing animation whereby strange things happen with circles and the colour of the window gets inverted. Screenshot - of just one moment of this weird parade, and using dark mode:

Whether or not this behaviour is by design, surely it should not occur.

I am about to extend my license anyway . . :)

The OS at issue: Windows

[RealRaven2000]

Ok, thanks for the heads up looks weird. the whole background of the window should be dark (at least it is here in dark mode) and then there will be a slight shadow over the background when you hove on the Exten License button:

once you move away from the button there is a contracting elliptical shadow focusing towards the button:

I also get the same when I set the Theme to "system" = which will get the coloring from windows, which is set to dark mode here. What does a system diualog look like on yours? You can display one if you right click a folder on the left and select properties:

The QF preferences dialog should have the same background color.

[LinuxOnTheDesktop]

What does a system diualog look like on yours? You can display one if you right click a folder on the left and select properties

Here is a screenshot of what I see when I use the display theme within Thunderbird called 'dark'.

I wonder whether my css is as follows - though having extended the license I seem unable to test that hypothesis. Here is my C:\Users\Nicholas\AppData\Roaming\Thunderbird\Profiles\gl2ero0t.default-release\chrome\userChrome.css file.

/* For Thunderbird /<userPath>/.thunderbird/<profile>/chrome/userChrome.css */

/* For alternating rows - for use with Thunderbird version >=115 version under the 'dark' theme */
@namespace html url("http://www.w3.org/1999/xhtml");
#threadTree tr:nth-child(2n) {
  background-image: linear-gradient(rgba(255,255,255,.15), rgba(255,255,255,.15)) !important;
}