Hello
Best solution in your case is to enlarge the block width for lg screens that actually has 9 as grid width and 3 for the contact-us module space changing to 10 and 2
To do this go to this file /templates/ja_platon/tpls/blocks/mainnav.php and find this code
<div class="t3-navbar navbar-collapse collapse <?php if ($headright) echo 'col-xs-2 col-lg-9' ?>">
change it to :
<div class="t3-navbar navbar-collapse collapse <?php if ($headright) echo 'col-xs-2 col-lg-10' ?>">
then find
<div class="col-xs-8 col-md-6 col-lg-3 pull-right">
and change to :
<div class="col-xs-8 col-md-6 col-lg-2 pull-right">
This will enlarge mainnav block width to allow more menu items in a single row
Regards