*{
margin:0;
padding:0;
box-sizing: border-box;
width:100%;
height: 100%;
}
.main {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  overflow-y: hidden;
  height: 100vh;
  width: 100vw;
  background-image: url(Navidad.jpg);
  background-size: cover;
}
@media only screen and (max-width: 390px){
  .main .vid{
    transform: rotate(90deg);
  }
}