Change The Font Mid-Story

I am using Harowe. I currently have two (and am planning on getting more) fonts which I'd like to put into my story. I've imported them both, and I know how to change the font, I just don't know if I can change the font mid-story. I have a passage tagged title and another tagged main. Here's my stylesheet:

@import 'https://fonts.googleapis.com/css?family=Roboto+Condensed';

@import 'https://fonts.googleapis.com/css?family=Arimo';

html.main tw-story {
	font-family: 'Arimo', sans-serif;
}

html.title tw-story {
	font-family: 'Roboto Condensed', sans-serif;
}

However, this doesn't work. Can you change the font? Or can there only be one font throughout a story?