blink, .blink {
  -webkit-animation: blink 1s step-end infinite;
  -moz-animation: blink 1s step-end infinite;
  -o-animation: blink 1s step-end infinite;
  animation: blink 1s step-end infinite;
}

@-webkit-keyframes blink {
  67% { opacity: 0 }
}

@-moz-keyframes blink {
  67% { opacity: 0 }
}

@-o-keyframes blink {
  67% { opacity: 0 }
}

@keyframes blink {
  67% { opacity: 0 }
}