main{
    line-height: 1.8rem;
    border: solid #000;
    background-color: #eeeeee;
    box-shadow: inset 0px 0px 10px;
    padding: 5%;
}

#title{
    text-align: center;
}

h2{
    text-align: center;
    font-family: "Yu Mincho", Georgia, serif;
    font-size: 200%;
    position: relative;
    display: inline-block;
    padding: 0 230px;
    margin-top: 0;
    margin-bottom: 5rem;
}

h2::before,
h2::after{
    content: '';
    position: absolute;
    top: 50%;
    display: inline-block;
    width: 200px;
    height: 3px;
    background-color: #000;
}

h2::before{
    left: 0;
    background: linear-gradient(-90deg, #000, transparent);
}

h2::after{
    right: 0;
    background: linear-gradient(90deg, #000, transparent);
}

#contents{
    max-width: 900px;
    line-height: 1.8rem;
    margin: 0 auto;
}

@media screen and (max-width: 750px){

    h2{
        padding: 0;
    }

    h2::before,
    h2::after{
        content: none;
    }
}