Edit in JSFiddle

* {
    background-color: black;    
}

a {
    position: relative;
    font-family: monospace;
    background-color: black;
    text-decoration: none;
    color: green;
    font-size: 1.5em;
}

.cursor {
    position: absolute;
    top: 0;
    bottom: 0;
    right: 0;
    width: 100%;
    background: black;
    box-sizing: border-box;
    
    -webkit-animation: typing 12s steps(13, end) infinite;
    animation: typing 12s steps(13, end) infinite;
}

@-webkit-keyframes typing {
    from,to { width: 100%; }
    25% { width: 0; }
    50% { width: 0; }
    75% { width: 100%; }
}

@keyframes typing {
    from { width: 100%; }
    to { width: 0; }
}