strong {
    animation-name: parpadeo;
    animation-duration: 1s;
    animation-timing-function: linear;
    animation-iteration-count: infinite;

    -webkit-animation-name: parpadeo;
    -webkit-animation-duration: 1s;
    -webkit-animation-timing-function: linear;
    -webkit-animation-iteration-count: infinite;
}

@keyframes parpadeo {
    0%{opacity: 1.0;}
    50%{opacity: 0.0;}
    100%{opacity: 1.0;}
}