Add this CSS classes :
ul{
float:right;
}
#brand {
float:left;
}
Add to .navButton
:
display: inline-block;
And add to #header
:
overflow:hidden;
Also replace :
width: 1140px;
with
min-width: 1140px;
width: 100%;
in #navMenu, #footer
and #header
.
Check Fiddle