.sigma-content{
    margin: 50px;
    text-align: center;
    background-color: #fff;
}
.sigma-middle-line:before{
    content: '';
    display: block;
    height: 1px;
    width: 100%;
    background-color: #999;/*颜色需与主题大背景色一致*/ 
    position: relative;
    top: 10px;/*调节线高*/
    left: 0;
}
.sigma-line-text{
    display: inline-block;
    background: #fff;
    padding: 0 18px 0 18px;
    position: relative;
    font-size: 14px;
    font-weight: 500;
    color: #888;
}