@media (max-width: 800px) {
  #index-about {
    background-image: url('/images/MAIN_Mobile.jpeg');
    /*background-position: left top !important;*/
    background-repeat: no-repeat;
    background-size: 100%;
  }
}

@media (min-width: 801px) {
  #index-about {
    background-image: url('/images/MAIN_Web.jpg');
    background-repeat: no-repeat;
    background-size: cover;
  }
}