body,dl,dd{margin: 0;font-family:"微软雅黑"}
body{color:#333;}
img{display: block;}
h1,h2,h3,h4,h5{margin: 0;font-size: 1em;font-weight: normal;font-family:"微软雅黑";}
p{margin: 0;}
ul{list-style: none;padding: 0;margin: 0;}
 input,textarea,select,a:focus {outline: none;}
a{text-decoration: none;color: white;margin: 0}/* CSS Document */


body{
width: 100%;
height: 100%;
overflow: hidden;
}

.bg{
background-image: url(../img/bg1.png);
background-repeat: no-repeat;
background-position: center center;
width:100%;
height:100%;
background-size:1920px 1080px;
position: fixed;
}

.bt{
font-size: 48px;
font-weight: bold;
color: #fff;
text-align: center;
width: 100%;
margin-top: 40px;
}

.box{
width: 1200px;
margin: 0 auto;
}

.logo{
margin-top: 60px;
width: 100px;
}

.logo img{
width: 100%;
}

.js{
font-size: 24px;
color: #fff;
text-indent: 48px;
margin-top: 20px;
line-height: calc(24px * 1.5);
}

@media (max-width: 768px) {
    .bg {background-size: 100% 100%;position: static;}
    .box {width: 90%;}
    .bt {font-size: 32px;}
    .js {font-size: 20px;}
    .logo {width: 60px;}
    body {overflow-y: scroll;}
 }

.logo {margin-top: 0;padding-top: 20px;}