Pulsating Arrow CSS Only

gistfile1.scss

/* arrow fades in and out, use for a 'scroll down' indicator for example */
#godown {
    position:absolute;
    bottom:20px;
    left:50%;
    margin-left:-10px;
    width:20px;height:20px;
    display:block;
    transform: rotate(45deg) ;
    -webkit-transform: rotate(45deg) ;
    -moz-transform: rotate(45deg) ;
    -o-transform: rotate(45deg) ;
    -ms-transform: rotate(45deg) ;
    .arrow {
        border-bottom:3px solid #333;
        border-right:3px solid #333;
        -webkit-animation: pulsate 1s ease-out;
        animation: pulsate 1s ease-out;
        -webkit-animation-iteration-count: 99;
        animation-iteration-count:00;
        opacity: 1.0;
        width:20px;height:20px;
        display:block;
        
    }
}

@-webkit-keyframes pulsate {
    0% {-webkit-transform: scale(1.0, 1.0); opacity: 0.0;}
    50% {opacity: 1.0;}
    100% {-webkit-transform: scale(1.0, 1.0); opacity: 0.0;}
}