.contact_info{
    max-width: 500px;
    /*padding: 15px;
    margin: 0 auto;*/
    border: 1px solid #dddddd;
    border-radius: 10px;
    box-shadow: 5px 5px 5px #aaaaaa;
    margin-left: auto;
    margin-right: auto;
    margin-top: 50px;
    /*内边距*/
    padding: 20px 40px;
}