.only_back{background-image: url(../img/backpic_relation.png);background-size: 100% 100%; background-repeat: no-repeat;height: 340px;width: 1000px;}
.wrapper_container{width: 800px;margin-left: 100px;}
.first_content{width:800px;height: 200px;padding-top:60px;}
.main_title{font-size: 3.5rem;font-weight: 300;line-height: 1.2;}
.main_two_title{font-size: 18px; font-weight: 300;display: block;margin-top: 20px;width: inherit;padding-bottom: 20px;color: dimgray;font-family: "微软雅黑";}
/*第二栏*/
.second_content{width: inherit;height: 2740px;}
.second_content>.small_title{display: block;width: 800px;text-align: center;font-size: 30px;line-height: 36px;font-weight: 900;color: rgb(0,166,231);padding-top: 20px;padding-bottom: 20px;}
.second_content>.small_content{text-indent: 2em;font-size: 18px;line-height: 36px;}
.second_content>div{width: 800px;margin-top: 60px;}
.second_content>div>.join_style{font-weight: 900;color: rgb(0,166,231);font-size: 36px;text-align: center;}