.fadeInOut {
    width:15px;
    height: 15px;
    background: #eb4034;
    border-radius: 50%;
    -webkit-animation: fadeinout 4s linear forwards infinite;
    animation: fadeinout 4s linear forwards infinite;
}

@-webkit-keyframes fadeinout {
    0%,100% { opacity: 0; }
    50% { opacity: 1; }
}

@keyframes fadeinout {
    0%,100% { opacity: 0; }
    50% { opacity: 1; }
}

#app {
    padding: 5px;
}