body {
    margin:0 auto;
    padding:0 0;
}
h4{
    font-family:"微软雅黑";
    color:darkblue;
}
.main {
    width:92%;
    height:540px;
    margin: 10px auto;
    border: 1px solid #d8c7c7; 
    text-align:center;  
    border-radius:4px;
}
.txt{
    border-radius:4px;
    border-width:1px;
    border-color:cornflowerblue;
    outline:none;
    font-family:"微软雅黑";
    font-size:14px;
}
.btn{
    width:80px;
    height:35px;
    background-color:dodgerblue;
    font-family:"微软雅黑";
    font-size:16px;
    color:#FFF;
    border-color:transparent;       
    border-radius:4px;
    
}
.btn:hover{
    background-color:darkcyan;
}

.auto-large {
    text-align: left;
    font-size: xx-large;
}

.auto-medium {
    color: darkblue;
    font-size: medium;
    font-family: "Microsoft YaHei UI";
    line-height: 30px;
    margin: 0px auto;
}

.auto-small {
    color: darkblue;
    font-size: small;
    font-family: "Microsoft YaHei UI";
}