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 }}
div {
    height: 200px;
    width: 400px;
    background: black;

    position: fixed;
    top: 50%;
    left: 50%;
    margin-top: -100px;
    margin-left: -200px;
}