.book_single {
  width: 96%;
  margin: 0 auto;
  padding: 32px 0 0;
}

.book_single-box {
  width: 100%;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: space-between;
  margin: 0 0 32px;
}

.book_single-img {
  flex-basis: 100%;
  position: relative;
  flex-direction: row;
}

.book_single-img>img {
  width: 100%;
  object-fit: contain;
}

.book_single-info {
  flex-basis: 100%;
  margin: 16px 0;
}

.book_single-ttl {
  font-size: 22px;
  color: #03827e;
  margin: 0 0 4px;
}

.book_single-subttl {
  font-size: 16px;
  color: #03827e;
}

.book_single-author {
  font-size: 16px;
  line-height: 1.3;
  color: #333;
  margin: 16px 0 0;
}

.book_single-author:last-of-type {
  margin: 0 0 24px;
}

.book_single-txt {
  font-size: 16px;
  line-height: 1.8;
  color: #333;
  margin: 0 0 24px;
}

.book_single-link {
  margin: 0 0 24px;
}

.book_single-link a {
  font-size: 16px;
  line-height: 1.8;
  color: #555;
  cursor: pointer;
}

.book_single-back a:link, .book_single-back a:visited, .book_single-back a:active {
  color: #555;
}

.book_single-supplement {
  margin: 0 0 32px;
}

.book_single-supplement-header {
  color: #616161;
  margin: 8px 0;
  font-size: 14px;
}

.book_single_collaborator_items {
  width: 100%;
}

.book_single_other-items {
  width: 100%;
}

.book_single-back {
  text-align: center;
  margin: 0 0 40px;
}

.book_single-back a {
  display: inline-block;
  margin: 0 auto;
  padding: 8px 20px;
  font-size: 16px;
  line-height: 20px;
  text-decoration: none;
  background-color: #000;
  color: #fff;
  border-radius: 18px;
}

.book_single-back a:link, .book_single-back a:visited, .book_single-back a:active {
  color: #fff;
}

@media screen and (min-width: 520px) {
  .book_single-img {
    flex-basis: 32%;
    margin: 0 0 16px;
  }

  .book_single-info {
    flex-basis: 65%;
    margin: 0;
  }

  .book_single-ttl {
    font-size: 28px;
    color: #03827e;
    margin: 0 0 4px;
  }
  
  .book_single-subttl {
    font-size: 16px;
    color: #03827e;
  }
  
  .book_single-author {
    font-size: 16px;
    color: #333;
    margin: 16px 0 0;
  }

  .book_single_txt {
    margin: 0 0 32px;
  }

  .book_single-supplement-header {
    font-size: 18px;
  }
}