*{
    margin: 0;
    padding: 0;
}
ul,li{
    list-style: none;
    padding: 0;
    margin: 0;
}
a{
    text-decoration:none
}

body{
    background-color: #000000;
    height: 100%;
    width: 100%;

}
html{
    font-family: "Helvetica Neue", Helvetica, STHeiTi, sans-serif;
    font-size: 20px;
    -webkit-user-select: none;
    -webkit-overflow-scrolling: touch;
    height: 100%;
    width: 100%;
}
@media (min-width: 400px) and (max-width: 480px) {
    html{
        font-size: 25px;
    }
}
@media (min-width: 480px) and (max-width: 640px) {
    html{
        font-size: 30px;
    }
}
@media (min-width: 640px) {
    html{
        font-size: 40px;
    }
}
.top-menu{
    position: fixed;
    overflow-y: scroll;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 1000;
    transition: max-height .8s ease;
    -webkit-transition: max-height .8s ease;
    -moz-transition: max-height .8s ease;
    overflow: hidden;
    max-height: 0;
}
.top-menu.show{
    max-height: calc(100vh);
}
.close-btn{
    position: absolute;
    top: 0;
    left: 0;
    width: .7rem;
    height: .7rem;
    padding: .7rem;
}
.close-btn:before{
    transform: rotate(45deg);
}
.close-btn:after{
    transform: rotate(-45deg);
}
.close-btn:before,
.close-btn:after{
    content: '';
    position: absolute;
    height: 2px;
    width: 1rem;
    top: 50%;
    left: .7rem;
    margin-top: -1px;
    background-color: #fff;
}

.menu{
    margin: 2.1rem auto 0;
    font-size: .6rem;
    /* padding: 0 0 1rem; */
    line-height: 4;
    background: rgba(0,0,0,.8);
    overflow: hidden;
    /* text-align: left; */
}
@media (max-height: 480px) {
    .menu > li{
        width: 50%;
        float: left;
        box-sizing: border-box;
    }
    .menu > li:nth-child(odd) > a{
        border-right: 1px solid #404040;
    }
}

.sub-menu > li{
    width: 25%;
}
.menu li{
    margin: 0 auto;
}
.menu a.open{
    border-bottom: 1px solid #fff;
}
.menu li a{
    border-bottom: 1px solid #404040;
}
.sub-menu > li > a{
    border-bottom: 1px solid #fff;
}
.menu a{
    text-decoration: none;
    color: #fff;
    text-align: left;
    display: block;
    padding: 0 .7rem;
    position: relative;
}
/*.menu a:after{*/
    /*position: absolute;*/
    /*content: '';*/
    /*width: .7rem;*/
    /*height: .7rem;*/
    /*transform: rotate(45deg);*/
    /*border-top: 1px solid #909090;*/
    /*border-right: 1px solid #909090;*/
    /*right: .7rem;*/
    /*top: .8rem;*/
/*}*/
.sub-menu{
    max-height: 0;
    overflow: hidden;
    transition: max-height .4s linear;
    -webkit-transition: max-height .4s linear;
    -moz-transition: max-height .4s linear;
}
.sub-menu.show{
    max-height: 400px;
}

header{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 2.1rem;
    background-color: rgba(0, 0, 0, .9);
    z-index: 500;
    text-align: center;
}

.menu-btn{
    position: absolute;
    padding: .7rem;
    top: 0;
    left: 0;
    width: 1rem;
    height: .7rem;
}
.menu-btn:before{
    content: '';
    position: absolute;
    height: 2px;
    width: 1rem;
    top: 50%;
    left: .7rem;
    margin-top: -1px;
    background-color: #fff;
}
.menu-btn:after{
    content: '';
    position: absolute;
    top: .7rem;
    left: .7rem;
    width: 1rem;
    height: .7rem;
    margin-top: -2px;
    border-top: 2px solid #fff;
    border-bottom: 2px solid #fff;
}
.logo{
    margin-top: .7rem;
    height: .7rem;
    display: inline-block;
}
.top-menu2{
    width: 100%;
    height: 1.5rem;
    line-height: 1.5rem;
    background: #121212;
    position: fixed;
    z-index: 150;
    top: 2.1rem;
    left: 0;
    justify-content: space-around;
    display: flex;
}
.top-menu2 a{
    font-size: 0.55rem;
    color: #6f6f6f;
}
.top-menu2 a.active{
    color: #fff;
}
.parameter{
    width: 100%;
    display: block;
    margin: 3.6rem 0 0;
}
#buy{
    display: block;
    color:#FFFFFF;
    width: 1.5rem;
    height: .9rem;
    background: #f08209;
    border-radius: .1rem;
    text-align: center;
    vertical-align:middle;
    line-height: .9rem;
    margin-top: .3rem;
}