@-moz-keyframes flash {
  0%, 50%, 100% {
    opacity: 1;
  }
  25%, 75% {
    opacity: 0;
  }
}
@-webkit-keyframes flash {
  0%, 50%, 100% {
    opacity: 1;
  }
  25%, 75% {
    opacity: 0;
  }
}
@-o-keyframes flash {
  0%, 50%, 100% {
    opacity: 1;
  }
  25%, 75% {
    opacity: 0;
  }
}
@keyframes flash {
  0%, 50%, 100% {
    opacity: 1;
  }
  25%, 75% {
    opacity: 0;
  }
}