XF 1.5 Font family - mobile devices

[MetalRush]

Today, after some startup problems, our forum moved from PHPBB to xenForo.
Something we should have done earlier....

We changed a lot via the templates and color palets.
Only thing which is bugging me, is the font family on mobile devices.
I changed almost all font families of all css files (perhaps not the smartest thing to do... but I'm learning here ). But my mobile devices (phone and tablet) still give me a 'Times New Roman" as default font on the message body.
Is there a way to change this?

 

[Paul B]

What have you changed the fonts to?

Are they web safe fonts?

If not, did you specify a fallback font?

 

[MetalRush]

Calibri.
Just checked; Nope.
No. I wanted to force the preferred font.
Due to your reply, it is clear to me that this does not work.
What do you advise?
And don't get me wrong; I did search extensively, but did not find the answers I was looking for. Now with your reply, I have more search options

Thanks, Brogan

[EDIT]
By the way: why are font names sometimes tagged by quotes and others are not?
E.g.: "Palatino Linotype", "Book Antiqua", Palatino, serif

 

[Paul B]

Font names with spaces due to having two or more words are enclosed in quotes.

If you don't use web safe fonts, you have to specify a fallback font.

http://www.w3schools.com/cssref/css_websafe_fonts.asp

 

[MetalRush]

Thanks, Brogan.
I just left that page and decided to take a web save font and a fall-back.
Issue with my mobile devices is solved with this solution/answer.
If I'm feeling better (having the flu atm) I will do three cheers for you