Userstyle.css doesn't change the font in the rendered markdown

Operating system

Windows

Joplin version

2.13.8

Desktop version info

Joplin 2.13.8 (prod, win32)

Client ID: b480c4dd8d6048cabfc034e658888ee6
Sync Version: 3
Profile Version: 44
Keychain Supported: Yes

Revision: 604dcbc

What issue do you have?

In the userstyle.css I wrote

 body { font-family: 'B Nazanin Regular', sans-serif; font-size: 18px; } 

but it has no effect on the rendered markdown
note that when I write the following in the editor it does change the font

<span style="font-family: 'B Nazanin', sans-serif; font-size: 18px;">
Your entire note content goes here.
</span>

see how one of thing I have written in the screen shot has default style although I have changed the userstyle.css

Screenshots

Try matching the font name in userstyle.css with the <span> tag, since the latter works.

Just noticed that the font is indeed changed it was the size that got me confused.