@media only screen and (max-device-width: 768px) {
  /* define mobile specific styles come here */
           html body {
             background-color: #000;
         }
}
@media only screen and (min-device-width: 769px) {
  /* define mobile specific styles come here */
           html body {
             overflow: hidden;
             height: 100%;
             background-color: #000;
         }
}