I think if you just add this:
#hilightbox {
background: url(../img/action-bg.jpg);
width: 100%;
margin: 20px auto;
overflow: hidden;
}
it will solve you problem.
currently your container div #hilightbox
does not know about child div's (.hilightbox-text
and hilightbox-action
) height
& width
because of float:left
property.