I used TINY_MCE plugin to have an advanced editor. The problem is that the default font used in this plugin is too small for me. Is it possible to change it? I mean the default font used for paragraph. As you can see below, the font is smaller that the font I used for other fields.

Thanks.
This is not that difficult. The easiest was will be to use the tinymce init paramter content_css
in this ccs file you need to set