*{
    margin:0;
    padding:0;
}
body {
    height:100%;
    margin-bottom:0;
}
.wrap {
    position:absolute;
    height:100vh;
    width: 100%;
    background:url(../picture/upgrade_maintenance.jpg) repeat center;
    text-align: center;
    margin:0 auto;
}
.wrap .title,.wrap p{
    color:#fff;
}
.wrap .title{
    font-size:70px;
    margin-top:11%;
}
.wrap p{
    font-size:22px;
    margin:1% 0;
}
.wrap p .kefu{
    color:#E8BA2A;
    text-decoration: none;
}
@media only screen and (max-width: 768px){
    .wrap .title{
        font-size:34px;
        margin-top:46%;
    }
    .wrap p{
        font-size:14px;
        margin:3% 0;
    }
}