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