.pdn {
    padding: 20px 100px 30px 50px;
}

@media (max-width: 767px) {
    .pdn {
        padding-left:20px;
        padding-right:20px;
    }
}
.pdn_title {
    text-align: center;
    font-size:20px;
    max-width:600px;
    margin:0 auto 30px auto;
    line-height: 1.2;
}


.pdn_chapter {
  margin-top:40px;
}

.pdn_chapter__title {
    font-weight: bold;
    line-height: 1.2;
    font-size:23px;
}

@media (max-width: 767px) {
    .pdn_chapter__title {
        font-size:20px;
    }
}

.pdn_chapter li {
    margin-bottom: 10px;
}