html,body{
    margin:0;
    padding:0;
    background: #fff url("main_bg.png") no-repeat center /cover;
    color:#333;
    font-family: "Microsoft YaHei", "微软雅黑", "Helvetica Neue", Helvetica, Arial, sans-serif;
    height: 100%;
    width: 100%;
    overflow: hidden;
}
a {
    border: none;
    outline: none;
    color: #222;
    text-decoration: none;
    -webkit-transition: color 0.1s;
    -moz-transition: color 0.1s;
    -o-transition: color 0.1s;
    transition: color 0.1s;
}

a:hover {
    color: #e1afa1;
}

img {
    border: none;
    outline: none;
}

h1, h2, h3, h4, ul, li, dl, ol, p, table, td, dd {
    padding: 0;
    margin: 0;
}

ul, li, ol, dl, dt, dd {
    list-style: none;
}
.w1600 {
    margin:0 auto;
    max-width: 1600px;
}

header.header{
    position: fixed;
    z-index: 999;
    left:0;
    right:0;
    height: 56px;
    padding: 0 20px;
}
/*header.header div.pic{
    width: 375px;
    margin-top: -30px;
    overflow: hidden;
    border-radius: 36px;
}
header.header div.pic img{
    display: block;
    width:100%;
    height: auto;
}*/
nav.nav {
    margin: 30px auto 0;
    line-height: 56px;
    overflow: hidden;
    top: 0;
    display: flex;
    flex-direction: row;
    justify-content: space-between;
}
nav.nav > div{
    display: flex;
}
nav.nav a{
    color: #fff;
    margin: 0 20px;
}
nav.nav a:first-child {
    margin-left: 0;
}
nav.nav a:last-child {
    margin-right: 0;
}
nav.nav a img{
    display: block;
    max-height: 54px;
}


section.sec{
    position: absolute;
    overflow: hidden;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
}

section.sec_1 div.pic{
    width: 375px;
    overflow: hidden;
    border-radius: 36px;
    position: absolute;
    left: 50%;
    top: -30px;
    transform: translateX(-50%);
}
section.sec_1 div.pic img{
    display: block;
    width:100%;
    height: auto;
}
section.sec_1 div.pic.bottom-pic {
    bottom: -30px;
    top: unset;
}

section.sec div.container {
    position: absolute;
    width: 90%;
    max-width: 800px;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -60%);
    color: #fff;
    text-align: center;
    line-height: 1.8;
    font-size: 14px;
}
section.sec div.container h3{
    font-size: 36px;
    font-weight: normal;
    margin-bottom: 20px;
}
section.sec div.container div.download-wrapper {
    margin-top: 50px;
    text-align: center;
}
div.download-wrapper a{
    display: inline-flex;
    padding: 5px 20px;
    line-height: 32px;
    border: 1px solid #fff;
    border-radius: 60px;
    font-size: 18px;
    min-width: 120px;
    color: #fff;
    margin: 0 15px;
    justify-content: center;
    align-items: center;
    transition: all .2s;
}
div.download-wrapper a img{
    display: block;
    height: 28px;
    margin-right: 5px;
}
div.download-wrapper a:hover{
    background: #000;
    border-color: #000;
    box-shadow: 0 0 10px #fff;
}

section.sec_2{
    display: none;
}
section.sec_2 {
    padding: 0 20px;
}
section.sec_2 div.body{
    max-width: 800px;
    margin:0 auto;
    position: absolute;
    left:50%;
    top:50%;
    transform: translate(-50%, -50%);
    color: #fff;
    white-space: pre-line;
    opacity: .8;
}

footer.footer{
    position: absolute;
    left:0;
    right:0;
    bottom:0;
    height: 56px;
    padding: 0 20px;
    background: #fff;
    font-size: 14px;
    text-align: center;
    opacity: .8;
    z-index: 9999;
}
footer.footer div{
    max-width: 600px;
    margin:0 auto;
    line-height: 56px;
}