adapting the layout to fit more viewports

Starting to make the layout more flexible with some media queries; right now this should increase support for viewports down to about 750px in width. 

Meta viewport is also now set to 1.0, which should fix both mobile and tablet zoom issues as discussed here https://meta.discourse.org/t/mobile-viewport-not-being-set-correctly-so-things-are-too-small/17324