.bg {
  padding-top: 150px;
  background-image: url(../img/bg.png);
}

.header-border {
  z-index: 0;
}

@media (max-width: 450px) {
  .bg {
    padding-top: 100px;
    background-image: url(../img/bg_sp.jpg);
  }
}

.post {
  position: relative;
  z-index: 2;
}

.post-wrapper {
  width: 100%;
  padding: 9% 11%;
  z-index: 1;
  border-radius: max(15px, 1.56vw);
  box-shadow: 0 1px 20px rgba(0, 0, 0, 0.16);
  background-color: #fff;
}

p.sub-area {
  justify-content: flex-start;
  gap: 20px;
  margin-bottom: 40px;
  font-size: max(1.2rem, 0.83vw);
  font-weight: 700;
}

.cat {
  display: block;
  width: 112px;
  background-color: #fff;
  border-radius: 2em;
  text-align: center;
  font-size: 1.2rem;
  line-height: 2;
  color: #fff;
}

.cat.cat-news {
  border: 1px solid #fe45be;
  background-color: #fe45be;
}

.cat.cat-column {
  border: 1px solid #0350ff;
  background-color: #0350ff;
}

.cat.cat-topics {
  border: 1px solid #fcc745;
  background-color: #fcc745;
}

.post-title {
  display: block;
  margin-bottom: 66px;
  position: relative;
  font-size: max(2rem, 1.46vw);
  font-weight: 700;
  line-height: normal;
}

.post-title::after {
  content: "";
  display: block;
  width: 100%;
  height: 6px;
  position: absolute;
  bottom: -26px;
  left: 0;
  transform: translateY(-100%);
  background-image: linear-gradient(100deg, #0350ff, #fe45be, #fcc745);
}

.thumbnail {
  width: 100%;
  aspect-ratio: 43 / 24;
  margin-bottom: 30px;
  border-radius: max(15px, 1.56vw);
}

.post-wrapper h3 {
  margin: 60px auto 30px;
  padding-left: 15px;
  position: relative;
  font-size: max(1.8rem, 1.15vw);
  line-height: normal;
}

.post-wrapper h3::before {
  content: "";
  display: block;
  width: 3px;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  background-image: linear-gradient(#0350ff, #fe45be, #fcc745);
}

.page-nation {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 16px;
  margin: 0 auto;
  padding: 120px 0 200px;
}

.page-number a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100px;
  height: 100%;
  border-radius: 3em;
  box-shadow: 0 1px 10px rgba(0, 0, 0, 0.16);
  background-color: #fff;
  font-style: italic;
  font-size: 1.4rem;
  font-weight: 700;
  text-indent: -0.1em;
  color: #363636;
}

.page-number.next a,
.page-number.prev a {
  width: 70px;
  background-image: linear-gradient(100deg, #0350ff, #fe45be, #fcc745);
  font-size: 1.8rem;
  color: #fff;
}

@media (max-width: 450px) {
  .post-wrapper {
    padding: 15% 3%;
  }

  .post-title {
    margin-bottom: 44px;
  }

  .thumbnail {
    aspect-ratio: 7 / 4;
    margin-bottom: 20px;
  }

  .post-index {
    margin: 50px auto 20px;
  }

  .page-nation {
    display: flex;
    align-items: stretch;
    justify-content: center;
    gap: 8px;
    margin: 0 auto;
    padding: 80px 0;
  }

  .page-nation {
    padding: 80px 0;
  }
}