.loading:after {
    overflow: hidden;
    display: inline-block;
    vertical-align: bottom;
    -webkit-animation: ellipsis steps(4, end) 900ms infinite;
    animation: ellipsis steps(4, end) 900ms infinite;
    width: 0;
    content: '...';
}

@keyframes ellipsis {
    to {
        width: 30px;
    }
}

@-webkit-keyframes ellipsis {
    to {
        width: 30px;
    }
}