.tian {
    height: auto;
    margin-top: 18px;
    padding-left: 31px;
    width: 40%;
}
.my{
    width:100%;
    height:100%;
    position: relative;
    -webkit-box-shadow:0 2px 4px #dfe1e5,0 -1px 1px #dfe1e5;
    -moz-box-shadow:0 2px 4px #dfe1e5,0 -1px 1px #dfe1e5;
    box-shadow:0 2px 4px #dfe1e5,0 -1px 1px #dfe1e5;
    background: #fff;
}
/*提交按钮*/
.submit_div {
    position: absolute;
    bottom: 25px;
    left: 50%;
    margin: 0;
    margin-left: -185px;
    width: 370px;
}