The Fonts options you set seems not like we suggested. Please see this screenshot bellow:
After you set the Fonts options, now you need to setup your post title to have BOLD or ITALIC style. Please look at sample of our post:
As you can see, to make bold title its wrap with <strong></strong> tag (marked with red line). And to make italic its wrap with <em></em> (blue line).
If you not familiar with html tag, you could create this in your post content in Visual mode, then copy it from Text mode.
Please let us know if you still have questions.