Remove menu border hidden style on hover

Perhaps this is just unfinished, but right now when you hover over menu
items, the right border disappears which changes the width of the
element and causes all menu items after the hovered one to reflow. It
looks fine to me without hiding it. (My gut is that this was borrowed
from another menu where this made sense.)
Update jumbo email placeholder to be more readable

Just some new styles to make this more readable, and match the font that
would eventually be used when someone starts typing.
Merge pull request #154 from SlexAxton/slexaxton-menufix

Fix some styles on home page (menu and email placeholder)