Full Width menu above tabs creates a max-width 80% container??

When I insert a full width sub menu above enfold tabs, the following css get applied..and its not in my child css..

.responsive .container {
max-width: 80%;
}

So all content/theme files below the menu are at 80%..event the footer..theme etc.
If I move the menu down below the tabs, its fine.

Help please!!