.art-nav .art-menu-btn 
{
   border: 1px solid #404040;
   border-radius: 3px;
   box-shadow: 0 0 3px 0 rgba(0, 0, 0, .2);
   display: none;
   background: -ms-linear-gradient(top, #707070 0, #000 100%);
   background: -moz-linear-gradient(top, #707070 0, #000 100%);
   background: -o-linear-gradient(top, #707070 0, #000 100%);
   background: -webkit-gradient(linear, left top, left bottom, color-stop(0, #707070), color-stop(1, #000));
   background: -webkit-linear-gradient(top, #707070 0, #000 100%);
   background: linear-gradient(to bottom, #707070 0, #000 100%);
   margin: 3px;
   padding: 5px;
   position: relative;
   width: 20px;
}

.art-nav .art-menu-btn span 
{
   background: #E0E0E0;
   border-radius: 2px;
   display: block;
   height: 3px;
   margin: 3px 1px;
   position: relative;
   -moz-transition: background .2s;
   -o-transition: background .2s;
   -webkit-transition: background .2s;
   transition: background .2s;
}

.art-nav .art-menu-btn:hover span
{
   background: #f3f3f3;
}

#art-resp {
   display: none;
}

@media all and (max-width: 899px)
{
    #art-resp, #art-resp-t { display: block; }
    #art-resp-m { display: none; }
}

@media all and (max-width: 480px)
{
    #art-resp, #art-resp-m { display: block; }
    #art-resp-t { display: none; }
}