@James: You can try adding in the following CSS in “Appearance => Theme Options => Custom CSS” box.
#header-image,
#header-menu {
margin: 0 auto;
width: 1190px;
}
@media screen and (max-width: 1224px) {
#header-image,
#header-menu {
width: 1024px;
}
}
@media screen and (max-width: 1060px) {
#header-image,
#header-menu {
width: 900px;
}
}
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px)
and (orientation : landscape) {
#header-image,
#header-menu {
width: 960px;
}
}
@media screen and (max-width: 960px) {
#header-image,
#header-menu {
width: 700px;
}
}
@media screen and (max-width: 767px) {
#header-image,
#header-menu {
width: 380px;
}
}
@media only screen
and (min-width: 480px)
and (max-width: 767px) {
#header-image,
#header-menu {
width: 440px;
}
}
@media screen and (max-width: 479px) {
#header-image,
#header-menu {
width: 300px;
}
}
@media screen and (max-width: 320px) {
#header-image,
#header-menu {
width: 95%;
}
}