Steps to replicate the issue (include links if applicable):

• Use Firefox browser on Windows OS, Vector 2022 skin and a Wikipedia branch with complex latin letters (with diacritics) or non-latin alphabets like Arabic Wikipedia.

What happens?:

• Non-latin characters are presented as square symbols in h1, h2, and sticky headers because these symbols are not part of Windows Times font. It seems that this problem occurs since about two days.

• The problem is caused by CSS rules like the following one:

@media screen
.mw-body h1, .mw-body-content h1, .mw-body-content h2 {
  font-family: 'Linux Libertine','Georgia','Times',serif;
  line-height: 1.3;
}

On Windows systems usually Times font is used which contains only a small part of Unicode letters. "Times New Roman" font should be added.

What should have happened instead?:

• Non-latin letters should be presented as normal letters.

Software version (skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):

• Firefox 106.0.5
• Windows 22H2 19045.2251
• Vector 2022 skin