.header:not(.sticky) {
    position: absolute;
    left: 0;
    top: 1.5625vw;
    z-index: 100;
    width: 100%;
}

.full-menu.sticky {
    top: 20px;
    position: sticky;
    z-index: 999;
    -webkit-animation: stuckMoveDown .6s;
    animation: stuckMoveDown .6s;

}

.header .box {
    width: 74vw;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(17.25px);
    padding: 10px 3vw;

    border-radius: 50px;
    transition: all 600ms;
}

.full-menu.sticky .box {
    background: rgba(50, 50, 50, 0.6);
    backdrop-filter: blur(30px);
}

.header .box .l {
    display: flex;
    align-items: center;
}

.header .box .l .header-menu {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-left: 2vw;
}

.header .box .l .site-branding img.custom-logo {
    max-width: 3vw;
    transition: all 600ms;
}

.header .box .r {
    display: flex;
    align-items: center;
    height: 100%;
    justify-content: flex-end;
}

.header .box .r .buy {
    border-radius: 1.82292vw;
    border: 1px solid #FFF;
    transition: all 600ms;
}

.header .box .r .buy a {
    padding: .26042vw .78125vw;
    color: #fff;
    font-size: .78125vw;
    display: block;
    font-weight: 400;
    position: relative;
    transition: all 600ms;
    text-decoration: none;
}

.header .box .r .lan {
    display: flex;
    align-items: center;
    font-size: .72917vw;
    margin-left: 1.66667vw;
}

.header .box .r .lan .icon {
    margin-right: 4px;
}

.header .box .r .lan .icon img {
    display: block;
    transition: all 600ms;
    width: 1.04167vw;
}

.header .box .r .lan .zh {
    color: #FFF;
    transition: all 600ms;
    /* font-family: 'Arial'; */
    text-decoration: none;
    font-weight: normal;
}

.header .box .r .lan .en {
    color: #B9B9B9;
    transform: translateY(1px);
    /* font-family: 'Arial'; */
    font-weight: normal;
    text-decoration: none;
}

.header .box .r .lan span {
    color: #B9B9B9;
    margin: 0 4px;
    transform: translateY(1px);
}

@media screen and (max-width: 1200px) {
    .site-header {
        background-color: #353539;
    }

    .header .box {
        width: 100%;
        padding: 0 2vw;
    }
}

@media screen and (max-width: 990px) {
    .header:not(.sticky) {
        top: 0;
    }

    .header .box {
        background-color: inherit;
        backdrop-filter: inherit;
        padding: 5px 0;
    }

    .header .box .l {
        justify-content: space-between;

    }

    .header .box .l .site-branding img.custom-logo {
        max-width: 10vw;
    }

    .header .box .r {
        display: none;
    }
    .full-menu.sticky{
        top: 0;
    }
}