Change font size

-Try using Firefox with the Firebug add-on for this kind of CSS work. https://getfirebug.com/

Thank you very much for your help but… doesn′t exist something easier? I just want to change the font size of the whole blog to a bigger one.

The font size is controlled via your CSS, that really is the way to find out what needs to be changed in your style.css file.

Additionally, you may want to consider creating a child theme too. CSS changes like that are the best use for child themes.

also, as you have paid for your theme, ask for support from the theme’s seller.

the theme seems to have a support forum: https://www.kriesi.at/support/forum/propulsion