Chinese UI font fallback selects installed decorative fonts on Windows 11

[Aoisonic]

Environment
Jasna version: 0.10.0
Operating system: Windows 11
Interface language: Simplified Chinese
Problem
The Chinese UI font is displayed incorrectly on my computer. Some Chinese characters are rendered using decorative/artistic fonts that I installed for graphic design, instead of a normal system font such as Microsoft YaHei or SimSun.

For example, labels such as 系统检查 and other Chinese interface text do not use a normal UI font.

The source code appears to define the Windows font family as return "Segoe UI", "Consolas".

Since Segoe UI does not contain complete Chinese glyphs, the Tk/CustomTkinter font fallback seems to select one of the installed decorative Chinese fonts.

Additional testing
I have installed Microsoft YaHei UI and configured the Windows font fallback settings, but the problem still occurred.

After uninstalling several 造字工房 decorative fonts, the font displayed by Jasna changed. This suggests that the application or Tk font fallback is selecting those fonts for Chinese characters.

Expected behavior
Chinese interface text should use a normal sans-serif system font, for example:

Microsoft YaHei UI
Microsoft YaHei
Noto Sans CJK SC
It would also be helpful to have a UI font setting or a platform-specific Chinese font fallback.

Possible solution
For Windows, the default font could perhaps use Microsoft YaHei UI instead of Segoe UI for the main interface font.

Alternatively, the application could provide a font selection option or explicitly configure the Chinese font fallback.

Thank you for your work on Jasna.

中文说明
Windows 11 下，Jasna 0.10.0 的中文界面会错误地使用我安装的造字工房艺术字体，而不是微软雅黑或宋体。即使系统已经安装 Microsoft YaHei UI，并设置了 Windows 字体回退，问题仍然存在。

我卸载几个造字工房字体后，Jasna 的显示字体确实发生了变化，因此推测 Tk/CustomTkinter 在 Segoe UI 缺少中文字符时，错误地选择了这些艺术字体。

希望能够：

增加界面字体选择功能；
或者针对 Windows 使用 Microsoft YaHei UI 作为中文界面字体；
或者改进中文字体回退机制。

[Kruk2]

That looks a bit like your computer issue I think. One user reported it and he was lacking some fonts?
Not sure if there are any Chinese users here who can confirm this problem or say that it works for them. I'm not that much familiar with Chinese typings/fonts

[Aoisonic]

Thanks for the reply. I checked this carefully, and it does not seem to be caused by missing fonts.

My Windows 11 system already has the standard fonts installed, including Segoe UI, Microsoft YaHei, Microsoft YaHei UI and SimSun. However, Jasna's Chinese characters are rendered using some decorative Chinese fonts that I installed for graphic design.

The English text looks normal, but the Chinese text uses the wrong font. I also tested this by uninstalling several "造字工房" decorative fonts one by one. After uninstalling them, Jasna's Chinese font changed. This makes the problem reproducible and suggests that Tk/CustomTkinter is selecting those fonts during font fallback.

The source code seems to use:

return "Segoe UI", "Consolas"

Since Segoe UI does not contain all Chinese characters, the Chinese glyphs are resolved through font fallback. On my system, that fallback selects the decorative fonts instead of Microsoft YaHei or SimSun.

Could the Windows UI font be changed to Microsoft YaHei UI, or could Jasna explicitly configure a Chinese fallback font? Another possible solution would be a UI font setting.

[Kruk2]

I wonder why you're the first user to report it. Is your system special or no other Chinese user cares? For last months there was no change in UI fonts at all.
I definitely could setup fallback but it would be good to get some confirmation from another user which uses this language to better understand the problem.

[Aoisonic]

You may be right that my system is unusual. I have many Chinese decorative fonts installed for graphic design, so this may be a rare font-fallback issue.
However, the standard fonts are not missing: Segoe UI, Microsoft YaHei, Microsoft YaHei UI and SimSun are all installed. The issue is reproducible: uninstalling several “造字工房” fonts changes the Chinese font displayed by Jasna.
My guess is that Tk/CustomTkinter requests Segoe UI, and because it lacks Chinese glyphs, the fallback mechanism selects one of the installed decorative fonts. Users with only the default Windows fonts may never notice this, which could explain why I am the first person to report it.
An explicit Chinese fallback such as Microsoft YaHei UI would make the behavior more predictable, although I agree that confirmation from another Chinese user would be helpful.
Thank you for taking the time to reply to my issue despite your busy schedule.