body, html {
    min-height: 100%;
    margin: 0;
    padding: 0;
}

/* MOBILE FIRST */
 @media screen and (max-width: 1224px) {
  body {
    
    background-image: url("assets/img/mobilebk.jpg");
    background-position: center;
    background-repeat: no-repeat;
    -webkit-background-size: cover;
    background-size: cover;   
    -moz-background-size: cover;
    -o-background-size: cover;      
  }
} 
@media screen and (max-width: 640px) {
  body {
    background-image: url("assets/img/bkgroundGalaxy.jpg");
    background-position: center;
    background-repeat: no-repeat;
    -webkit-background-size: cover;
    background-size: cover; 
    -moz-background-size: cover;
    -o-background-size: cover;        
  }   
}

/* now the big guns */
@media screen and (min-width: 1224px) {
  body {
    background-image: url("assets/img/bkground.jpg");
    background-position: center;
    background-repeat: no-repeat;
    -webkit-background-size: cover;
    background-size: cover;  
    -moz-background-size: cover;
    -o-background-size: cover;      
  }
 
}