Hi there,
the css you showed above, change the last rule to:
nav#site-navigation > .inside-navigation > #primary-menu > ul > li:nth-child(4),
nav#site-navigation > .inside-navigation > #primary-menu > ul > li:first-child {
margin-left: auto;
}
Note we change this selector:
nav#site-navigation > .inside-navigation > #primary-menu > ul > li:last-child
to this:
nav#site-navigation > .inside-navigation > #primary-menu > ul > li:nth-child(4)
So it goes from targeting the last child to the 4th child.