It appears that your issue may be related to the way you are floating elements.
Upon inspecting the nav-selected nav-path-selected
in your navigation, it seems that its computed height is 0px.
This is a common problem that occurs when floated elements do not automatically resize their parent containers. When an element is floated, it is taken out of the normal flow of the document, causing its parent to no longer contain it. Different browsers may handle this differently, but a typical solution is to use a 'clearfix'.
If you include the following CSS code in your global stylesheet...
.clearfix:after {
content: ".";
display: block;
clear: both;
visibility: hidden;
line-height: 0;
height: 0;
}
.clearfix {
display: inline-block;
}
html[xmlns] .clearfix {
display: block;
}
* html .clearfix {
height: 1%;
}
And apply the clearfix class to elements with 0px height (such as nav-selected), you should see the element properly inheriting the correct height.