body {
  margin: 0;
  padding: 0;
}
.bakim {
  height: 100vh;
  width: 100%;
}
.bg {
  background: url("images/GUNCELLEME-3.jpg") center;
  background-size: cover;
  background-repeat: no-repeat;
  height: 100%;
  width: 100%;
}
@media only screen and (max-device-width: 728px) {
  /* CSS KODLARI BURAYA */
  .bg {
    background: url("images/mobile.jpg") center;
    background-size: cover;
    background-repeat: no-repeat;
    height: 100%;
    width: 100%;
  }
}