Tweak formatting of citation drop down

Now that we are using the large icons in the citation dropdown,
adjust the header margin so it still lines up vertically, also
slightly increase the font size from 0.8em to 0.9em so that it
doesn't look so tiny next to the icons.

Change-Id: I18c275e2bbf94a24dd2112b7e520b36d83c5cb15
Merge "Tweak formatting of citation drop down"