.skeleton-bg-img{
    position: absolute;
    left: 0;
    top: 0;
    z-index: 9999;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    background-image: url("skeleton-pc.png");
    background-size: 100% 100%;
}
@media screen and (max-width: 878px) {
    .skeleton-bg-img{
        background-image: url("skeleton-app.png")!important;
    }
}
/* 在伪类after中定义动画效果 */
.skeleton-bg-img::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 200%;
    height: 200%;
    opacity: 0.4;
    animation-duration: 2.25s;
    animation-fill-mode: forwards;
    animation-iteration-count: infinite;
    animation-name: shimmer;
    animation-timing-function: linear;
    background: #f6f7f8;
    background: linear-gradient(to right, #eeeeee 8%, #dddddd 18%, #eeeeee 33%);
    background-size: 800px 104px;
}
/* 定义动画，这里使用了CSS的@keyframes */
@keyframes shimmer {
    0% {
        background-position: -468px 0;
    }
    100% {
        background-position: 468px 0;
    }
}