I've come up with a general structure for the website now! The menu stuff has been removed temporarily, but will be added back soon
Adjusted the overflow of the middle container, so that it surrounds its content (hidden). The overflow will be dictated by the minimum width of the content container
Added a JavaScript file for displaying the drop down menus.

Updated the menus so that they are position absolute with z-index 2, so that they will appear over the top of the content below them.

The menus currently don't disappear unless you click them again. Need to look into adding jquery to the project, so that I can just hide all of the other menus dynamically.