Hi. This template is not responsive...
I would suggest that you smallen the jf_mainmenu ul li padding.
open file templates/jf_relaxio/css/template.css
#jf_mainmenu ul li a, #jf_mainmenu ul li a:visited {
display: block;
background: url(../images/jf_mainmenu.png) no-repeat top right;
line-height: 62px;
padding: 0px 34px;
text-transform: uppercase;
color: #FFF;
font-size: 13px;
text-shadow: 1px 0px 0px #600F25;
}
Change the padding for example to padding: 0px 14px;