nav {
   height:70px;
   background:black;
   position: fixed;
   top:0;
   right:0;
   left:0;
  transition: transform .25s .1s ease-in-out; 
   z-index:10003;
}

.down nav {
transform: translate3d(0, -70px, 0); 
}

.color nav {
   height:70px;
   background:black;
   position: fixed;
   top:0;
   right:0;
   left:0;
  transition: transform .25s .1s ease-in-out; 
   z-index:10003;
}



@media only screen and (max-width: 1000px) 
{
nav {height:50px; background:black;}
.color nav {height:50px;}
.down nav {transform: translate3d(0, 0px, 0); }
}