@media all and (orientation:landscape) and (max-device-width: 599px),
  (orientation:landscape) and (min-device-aspect-ratio: 16/9) and (max-device-width: 960px),
  (orientation:portrait) and (min-device-width: 600px) and (max-device-width: 1080px) {
    @-ms-viewport { width: 600px; }
    @viewport { width: 600px; }
  }

  @media all and (orientation:portrait) and (max-device-width: 599px) {
    @-ms-viewport { width: 325px; }
    @viewport { width: 325px; }
  }

  @media all and (min-device-width: 1081px) {
    @-ms-viewport { width: auto; }
    @viewport { width: auto; }
  }