.cat_ttl {
  font-size: 24px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 30px;
  line-height: 1.15;
  margin-bottom: 25px;
}
@media screen and (min-width: 769px) {
  .cat_ttl {
    font-size: 48px;
    gap: 40px;
    margin-bottom: 70px;
  }
}
.cat_ttl .num {
  display: block;
  font-size: 2.2em;
  width: 90px;
  height: 90px;
  border: 1px solid;
  border-radius: 50%;
  line-height: 87px;
  text-indent: 0.05em;
}
@media screen and (min-width: 769px) {
  .cat_ttl .num {
    font-size: 1.8em;
    width: 145px;
    height: 145px;
    border: 3px solid;
    line-height: 135px;
  }
}

.category_index {
  padding: 35px 0 100px;
}
@media screen and (min-width: 769px) {
  .category_index {
    padding: 55px 0 150px;
  }
}

.category_detail {
  padding: 35px 0 40px;
}
@media screen and (min-width: 769px) {
  .category_detail {
    padding: 70px 0 80px;
  }
}
.category_detail .ttl_block {
  border-bottom: 1px solid;
  padding-bottom: 40px;
  margin-bottom: 40px;
}
@media screen and (min-width: 769px) {
  .category_detail .ttl_block {
    padding-bottom: 80px;
    margin-bottom: 80px;
  }
}
.category_detail .detail_ttl {
  font-size: 15px;
  text-align: center;
  line-height: 1.36;
}
@media screen and (min-width: 769px) {
  .category_detail .detail_ttl {
    font-size: 30px;
  }
}
.category_detail .article h3 {
  font-size: 15px;
  line-height: 1.4;
  margin-bottom: 1em;
}
@media screen and (min-width: 769px) {
  .category_detail .article h3 {
    font-size: 26px;
  }
}
.category_detail .article p {
  margin-bottom: 1em;
}
@media screen and (min-width: 769px) {
  .category_detail .article p {
    margin-bottom: 1.5em;
  }
}
.category_detail .article img {
  object-fit: contain;
  aspect-ratio: 4/3;
}
.category_detail .article .archive_back_btn {
  margin-top: 40px;
}
@media screen and (min-width: 769px) {
  .category_detail .article .archive_back_btn {
    margin-top: 80px;
  }
}
.category_detail .article .archive_back_btn a {
  display: grid;
  place-content: center;
  width: 110px;
  height: 40px;
  border: 1px solid;
  margin: auto;
  position: relative;
}
@media screen and (min-width: 769px) {
  .category_detail .article .archive_back_btn a {
    width: 220px;
    height: 70px;
  }
}
.category_detail .article .archive_back_btn a::after {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  border-top: 1px solid;
  border-right: 1px solid;
  position: absolute;
  top: 50%;
  right: 10px;
  transform: translateY(-50%) rotate(45deg);
}
@media screen and (min-width: 769px) {
  .category_detail .article .archive_back_btn a::after {
    width: 12px;
    height: 12px;
    right: 15px;
  }
}