HTML5 and Me (HW help!)

[Carpe Vexillum]

So I've got this final project for my Interactive design class. We have to make a website. One that has a fluid design. I have hit a brick wall and need some assistance from some good fellow who might know a good amount of HTML5.

Now my end goal is to have the user click on one of the titles/graphic on the nav bar and to have a box with information appear in the content area of the website. When they close it, or click another link it will disappear or the information that they clicked will appear. And I want to do all of this without Java Script.

This is the skeleton for my site. It has a main navigation on the left that is fixed to the top.
site1.PNG

This is what I have using a :target operator for my div's content to appear in a CSS stylized box.
site2.PNG

The main problem I am having is that when I switch to an almost identical style (For my first Box I had to add a -margin hack to keep the hyper link from jumping down to the top of the appearing box) for my second, third, fourth, and fifth navigation headings, it snaps the page down to below the content area because I am assuming it wants to put the box there. And so on down the page. Plus, nothing actually appears. . . Does/can anyone help me get this working or at least point me in the right direction? I have provided my wip code if necessary.
stie3.PNG

CSS ------------------- HTML
48hour.txt ///////// index.txt