Changing fonts in circles, posts and pages

Hi Caroline, your theme is awesome. I managed to get most of my changes browsing this forum but I am struggling with changing the headline fonts. ive installed the google fonts plugin and the customs ccs plugin. Along with choosing my desired fonts using the google fonts plugin i have added this to the custom css:
container p { font-family: 'Cantara One'; }
this has resulted in the actual body text changing but but not the headline. What am i missing? Thanks!