.activity {
    position: absolute;
    left: -45%;
    height: 100%;
    width: 45%;
    background-image: linear-gradient(to left, rgba(251, 251, 251, .05), rgba(251, 251, 251, .3), rgba(251, 251, 251, .6), rgba(251, 251, 251, .3), rgba(251, 251, 251, .05));
    background-image: -moz-linear-gradient(to left, rgba(251, 251, 251, .05), rgba(251, 251, 251, .3), rgba(251, 251, 251, .6), rgba(251, 251, 251, .3), rgba(251, 251, 251, .05));
    background-image: -webkit-linear-gradient(to left, rgba(251, 251, 251, .05), rgba(251, 251, 251, .3), rgba(251, 251, 251, .6), rgba(251, 251, 251, .3), rgba(251, 251, 251, .05));
    animation: loading 1s infinite;
    z-index: 45;
}