.top-nav {
    height: 50px;
    margin-bottom: 525px;
}
.top-nav span{
    width: 100px;
     height: 45px;
     line-height: 45px;
     background-color: red;
     float: right;
     text-align: center;
 }
 .top-nav span a{
     color: #ffffff;
     font-size: 18px;
 }
 .top-by {
    height:auto;
    margin: 0 auto;
}
.top-by1{
    width: 75%;
    margin: 0 auto;
    
}
.top-by11{
    width: 100%;
    height: 224PX;
}
.top-by11 h1{
    width: 100%;
    margin: 0 auto;
    height: 74PX;
}



.footer{
    height: 156px;
    width: 100%;
    background: #f5f5f5;
    margin-top: 50px;
    border-top: 3px solid red;
    text-align: center;
}
.footer p{
    font-size: 14px;
    color: #333333;
    line-height: 30px;
}