.nav li a:first-child:nth-last-child(2):before { 
  content: ""; 
  position: absolute; 
  height: 0; 
  width: 0; 
  border: 5px solid transparent; 
  top: 50% ;
  right:5px;  
 }
/* submenu positioning*/
.nav ul {
  position: absolute;
  white-space: nowrap;
  border-bottom: 5px solid  grey;
  z-index: 1;
  left: -99999em;
}
.nav > li:hover > ul {
  left: auto;
  margin-top: 5px;
  min-width: 100%;
}
.nav > li li:hover > ul { 
  left: 100%;
  margin-left: 1px;
  top: -1px;
}
/* arrow hover styling */
.nav > li > a:first-child:nth-last-child(2):before { 
  border-top-color: #aaa; 
}
.nav > li:hover > a:first-child:nth-last-child(2):before {
  border: 5px solid transparent; 
  border-bottom-color: grey; 
  margin-top:-5px
}
.nav li li > a:first-child:nth-last-child(2):before {  
  border-left-color: #aaa; 
  margin-top: -5px
}
.nav li li:hover > a:first-child:nth-last-child(2):before {
  border: 5px solid transparent; 
  border-right-color: grey;
  right: 10px; 
}