.header {
    /* width: 19.2rem;  */
    width: 100%;
    height: 0.75rem;
    /* 75px */
    position: absolute;
    top: 0;
    left: 0;
    left: 50%;
    transform: translateX(-50%);
    transition: top 0s ease;
    z-index: 9100024;
    background-color: rgba(0, 0, 0, .7);
}

.header_top {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 0.16rem;
    /* 16px */
    height: 0.75rem;
    /* 75px */
    position: relative;
    box-sizing: border-box;

}

.logo_nav {
    /* width: 0.71rem;
    height: 0.5rem; */
    width: 0.82rem;
    height: 0.56rem;
    background: url(https://static.web.sdo.com/mxd/pic/mxdc_act/cv001/pc/logo_nav.png) no-repeat;
    background-size: contain;
}

.header_top_link {
    width: 0.8rem;
    display: flex;
    align-items: center;
}

.header_top_link_item {
    display: block;
    /* width: 50px; */
    margin-right: 0.3rem;
    font-size: 0.16rem;
    color: #ffff;
    white-space: nowrap;
}

.header_nav {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    /* height: 0.58rem; */
    height: 0.75rem;
    /* 75px */
}

.header_nav_item {
    line-height: 0.26rem;
    /* 26px */
    font-size: 0.26rem;
    /* 16px */
    font-weight: bold;
    color: #737174;
    text-align: center;
    width: 1.7rem;
    /* 100px */
    cursor: pointer;
    transition: all .3s;
    white-space: nowrap;
    border-right: 1px solid #655d3e;
}

.header_nav_item_active,
.header_nav_item:hover {
    color: #fff;
    filter: drop-shadow(0 0 0.2rem #fff);
}

.btn_tohome {
    width: 0.45rem;
    height: 0.45rem;
    background: url(https://static.web.sdo.com/mxd/pic/mxdc_act/cv001/pc/btn_toHome.png) no-repeat;
    background-size: contain;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    right: 2.1rem;
    /* 10px */
}

.top_bgm {
    width: 0.45rem;
    height: 0.45rem;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    right: 1.6rem;
    background: url(https://static.web.sdo.com/mxd/pic/mxdc_act/cv001/pc/bgm_top.png) no-repeat ;
}
.top_bgm_on{
    background: url(https://static.web.sdo.com/mxd/pic/mxdc_act/cv001/pc/bgm_top.png) no-repeat -0.45rem 50%;
    background-size: cover;
}
.top_bgm_off{
    background: url(https://static.web.sdo.com/mxd/pic/mxdc_act/cv001/pc/bgm_top.png) no-repeat 0 50%;
    background-size: cover;
}




.btn_download {
    width: 1.45rem;
    height: 0.48rem;
    background: url(https://static.web.sdo.com/mxd/pic/mxdc_act/cv001/pc/btn_download.png) no-repeat;
    background-size: contain;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    right: 0.1rem;
    /* 10px */

}

.btn-Sign {
    width: 1.9rem;
    height: 0.57rem;

    position: absolute;
    /* bottom: 0;
    right: 0; */
    top: 50%;
    transform: translateY(-50%);
    right: 0.05rem;
    background: url(../img/btn-Sign.png) no-repeat;
    background-size: contain;
}

.header.hide {
    display: none;
}