Template Issues?

Hi all, I have two issues which you may be able to help with. The first of which is the small thin white line that appears between the header bar and the feature image (especially within Chrome). It is only 1 or 2 pixels, but noticeable. The page is https://firstdropphotography.com/alton-towers/. The second enquiry has to do with SSL certificates. Every page, apart from the main home page appears secure, but the notice on the main page says that the connection is not fully secure? Could this be anything to do with the scrolling theme/sections?