Wysiwyg / css

Hi,

I just made a website with wordpress and now i styled the content on the website with like an font-family: arial and 12px; lineheight 18px.

But the user is not getting what he see’s in the wysiwyg editor. because this editor has his own style (bigger font, different font + other line height). Can i edit this ‘editor’ so the user see’s the matching results that are on the website?

If so how and where?

Kind regards