@media screen and (max-width: 640px)
{
   .TopNav a:not(:first-child) { display: none; }

   .TopNav a.icon
   {
      float: right;
      display: block;
   }
}  /* end @media screen and (max-width: 640px)  */

@media screen and (max-width: 640px)
{
   .TopNav.responsive  { position: relative;  }

   .TopNav.responsive .icon
   {
      position: absolute;
      right: 0;
      top: 0;
   }
   .TopNav.responsive a
   {
      float: none;
      display: block;
      text-align: left;
   }
}  /* end @media screen and (max-width: 640px) */