@media only screen and (max-width: 767px) {
  body {
    background-image: url("https://images.unsplash.com/photo-1483232539664-d89822fb5d3e?auto=format&fit=crop&q=80&w=1000&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxzZWFyY2h8Mnx8cGhvdG8lMjBiYWNrZ3JvdW5kfGVufDB8fDB8fHww");
  }
}

@media only screen and (min-width: 768px) {
  body {
    background-image: url("https://i.pinimg.com/originals/55/74/54/557454f9d762c6b6c9efdaec66b4dbb9.jpg");
  }
}
body{
  user-select: none;
}