$(function(){
  var totop = $('#to-top');
  //if($(window).width() > 768){
    $(".nav .item").hover(function(){
      var documentwidth = $(document).width();
      var navwidth = $(this).width();
      var navx = $(this).offset().left;
      var centerx = navx + (navwidth/2);
      var maxleft = (documentwidth - 1200) /2 +1200;
      var minleft = (documentwidth - 1200) /2;
      var boxwidth = 0;
      var left,maxwidth;
      var offsetleft = $(this).find('.icon-nav').length ? 104 : 54;
      $(this).find(".secord>li").each(function(){
        boxwidth += $(this).width() + offsetleft;
      });

      boxwidth-=offsetleft == 104 ? 0 : 54;
      if(boxwidth > 1200){
        boxwidth = 1200;
      }

      maxwidth = centerx + (boxwidth/2);
      if(maxwidth > 1200){
      	left = centerx  - (boxwidth/2) - (maxwidth - 1200);
      }else{
      	left = centerx - (boxwidth/2);
      	if(left < 0){
      		left = 0;
      	}
  	  }

      if(documentwidth > 1200){
        left = left - (documentwidth - 1200)/2;
      }

      if(documentwidth < 1200){
        $(this).find(".secord").css("margin-left","0px");
      }

      //$(this).find(".secord").css("position","relative");

      $(this).find(".secord").css("display","block");
      if($(this).find(".secord").css("margin-left") == "0px"){
        $(this).find(".secord").css("margin-left",left);
      }
    });
  //}

  //判断是否有滚动条
  totop.on('click',function () {
    $('body,html').animate({'scrolltop':0},300)
  });
  $(window).on('scroll',function () {
      if($(this).scrolltop() > 200){
        totop.show()
      }else{
        totop.hide()
      }
  })

 
});