*{
    padding: 0;
	margin:0;
    box-sizing: border-box;
}
body {

	background: url(../top.jpg) no-repeat center top;
	    background-size: contain;
		
}
.sm{
    width: 1300px;
    height: 1000px;
    background-color: #fff;
    margin: auto;
    margin-top: auto;
    margin-top: 27.5%; 
    border-style:solid;
    border-color:red;
}
.logo {
        margin-top: 30px;
    margin-left: 40px;
}
@media (max-width:767px){
body {
                        width: 100%;
                        background-image: url(../bjtp_wx.jpg);
                        background-repeat: no-repeat;
                  }  

        .logo{display:none;} 
.logo img{
	 width: 22%;
}
}