.ad_down {
    width: 100%;
    height: 15.6vw;
    position: fixed;
    bottom: 0;
    left: 0;
    z-index: 999;
    -moz-transform: translateX(0);
    -ms-transform: translateX(0);
    -webkit-transform: translateX(0);
    transform: translateX(0);
}

    .ad_down a {
        display: block;
        position: relative;
    }

        .ad_down a img {
            display: block;
            width: 100%
        }

    .ad_down iframe {
        display: block
    }

    .ad_down .arrow_banner {
        position: absolute;
        top: 5px;
        right: 5px;
        /* display: none; */
    }
    .ad_down .close_banner {
        position: absolute;
        bottom: 47vw;
        right: 5px;
        display: none;
    }
    .ad_down .close_banner_v {
        position: absolute;
        bottom: 217px;
        right: 5px;
        display: none;
    }
    /* 20220221修改start */
    .ad_down .ad_640x362 {
        position: absolute;
        bottom: -50px;
        opacity:0;
        transition: all 0.4s;
        pointer-events: none;
    }
    .ad_down .ad_show {
        bottom: 0;
        opacity:1;
        pointer-events: initial;
    }
    /* 20220221修改end */

    .ad_down .ad_640x362_v {
        position: absolute;
        bottom: -50px;
        opacity: 0;
        transition: all 0.8s;
        width: 100%;
        height: 250px;
    }
    .ad_down .ad_show_v {
        bottom: 0;
        opacity: 1;
    }