.container{
    margin: 0 5%;
    text-align: center;
}

/* 以下是标题部分 */
.container h3{
    display: inline-block;
    font-size: 1.8em;
    font-weight: 500;
    color: green;
    position: relative;
    margin-top: 2em;
    margin-bottom: 2em;
}
.container h3::before{
    content: "";
    display: block;
    border-bottom: 1px solid black;
    width: 51px;
    position: absolute;
    top: 49%;
    left: -70px;
}
.container h3::after{
    content: "";
    display: block;
    border-bottom: 1px solid black;
    width: 51px;
    position: absolute;
    top: 49%;
    right: -70px;
}

/* 以上是标题部分 */