editor-style vs style

I'm just trying out Catch Box and love the look and think it will work great for a non-profit I'm helping. I am curious why the styles in style.css and editor-style.css seem so different. For example, an H3 is 22px and bold on the front end which I like but the back end shows it in the editor as 10px and uppercase. Is there a reason for this or something I'm missing with the Theme Options or Pro version or something else? Thanks for the help! Andrew