You can add this css:
#nav-main ul.sf-menu {
float: left;
margin-left: -130px;
}
Also, just a note. I see you’ve added this:
.container {
width: 960px;
}
That completely throws off the responsiveness of your site. Try adding a media query around it:
@media (min-width: 992px) {
.container {
width: 960px;
}
}
Also if you want a menu on mobile be sure to select mobile navigation in Appearance > Menus.
Hannah