default font

what is the way to have in all articles arial font by default

Hello,

As I see on your page - articles have the Arial font in the text. Could you link to the subpage where you want to set the Arial font?

i want to be by default the arial font when writing a new article or when i copy from a document to the site to paste in arial font. can this happend?

As I wrote earlier - as I see the default font for the entries is Arial. When you copy the text it is not possible to set the default font, because when you are copying the text from documents like Word files then it is copied with inline styles which overrides the template CSS code.