.skeleton {
        position: relative;
        overflow: hidden;
        background: #ccc;
    }

        .skeleton::after {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, #ccc, #dedede, #ccc);
            animation: progress 1s ease-in-out infinite;
        }

    @keyframes progress {
        0% {
            transform: translate3d(-100%, 0, 0);
        }

        100% {
            transform: translate3d(100%, 0, 0);
        }
    }