The character "ς" don't appear

Hello.
Congratulations for your extension.
It's working fine except a small problem on mobile phone.
The character "ς" don't appear.
Can I change the fonts?

Hi and thank you
yes you can change the fonts in the camera.css file of the theme in the module
CEd

Thank you for your suggestion, but on camera.css I don't see the command about font family.
Now in website the font family is Droid sans.

there is no font-family but you can add your own here
I don't see why this character is not shown correctly ...

Probably the problem happens only in google chrome for mobile.
On my desktop the fonts appears ok.
Can you suggest me a command line in order to change the "Droid Sans" font family in camera.css
Thank you in advance.

you can try to add as an example