:root {
    --loading-grey: #ededed;
}
.is_loading {
    background-color: var(--loading-grey);
    background: linear-gradient(100deg,
            rgba(255, 255, 255, 0) 40%,
            rgba(255, 255, 255, .5) 50%,
            rgba(255, 255, 255, 0) 60%) var(--loading-grey);
    background-size: 200% 100%;
    background-position-x: 180%;
    animation: 1s loading ease-in-out infinite;
}
@-webkit-keyframes loading {
    to {
        background-position-x: -20%;
    }
}
@keyframes loading {
    to {
        background-position-x: -20%;
    }
}