How to set same font in every category

Hello, I need to set the font of every my article in every category i created in my site. I would like to have "verdana" as font-family and 12px as max height.

I tried to change k2.css file at this point:

.latestItemDateCreated,.genericItemDateCreated,.userItemDateCreated,.catItemDateCreated {
font-size: 12px;
font-family: Verdana;
}

it worked for a week, than it changed and now i can't restore it. Can you help my?

The easiest way is to set fonts via template settings ('Font' tab). Please paste selectors to one of group visible there, choose standard font and Verdana and then just save your settings.

Hello, I followed your instruction but it doesn't still work.
I noticed that other parts of the site changed font while i was modifying font option and selectors, but artilcles font and categories font didn't.

Could you send me direct link to page where you want to change font ? It will be easier for me to check CSS via Firebug.