This is a bit wrong
.top-pic {
position: absolute;
top: -5.7em;
right: -1.5em;
z-index: 1;
}
Cut this image into 2 images (one in the header next to the tabs, and one in the content). Stuff is floating underneath because of your z-index.
In your CSS. What you want is a pretty basic fixed 3-col layout with the text in the middle. I will point you here:
That is how CSS layouts are done.