nav{
  width: 100%;
}

.carousel{
  height: 700px;
  margin-top: -55px;
  position: relative;
  z-index: 1;
} 

@media screen and (max-width: 850px) {
  .carousel{
    height: 700px;
    margin-top: 1px;
    position: relative;
    z-index: 1;
  }
  nav {
    /* position: absolute; */
    width: 100%;
    top: 20px;
}
}