Hi Andy,
Hmm, you could try something like this:
.inside-header {
display: -webkit-box;
display: -moz-box;
display: -ms-flexbox;
display: -webkit-flex;
display: flex;
-webkit-flex-flow: row wrap;
flex-flow: row wrap;
}
.header-widget {
-webkit-box-ordinal-group: 5;
-moz-box-ordinal-group: 5;
-ms-flex-order: 5;
-webkit-order: 5;
order: 5;
}
.main-navigation {
-webkit-box-ordinal-group: 4;
-moz-box-ordinal-group: 4;
-ms-flex-order: 4;
-webkit-order: 4;
order: 4;
}