.nav-wrapper {
  background-image: url(../img/link_top_hp.jpg);
  background-position: center center;
  background-repeat: no-repeat;
  background-size: cover;
}
.hero {
  position: fixed;
  width: 90px;
  z-index: 1;
  transition: 0.5s; /* ======追記====== */
}

/* ======フッターまでスクロールするとナビゲーション非表示ここから====== */
.is-hidden {
  visibility: hidden;
  opacity: 0;
}
/* ======フッターまでスクロールするとナビゲーション非表示ここまで====== */

h2 {
  position: absolute;
  top: 500px;
  right: 40px;
}
h2 p {
  display: inline-block;
  text-align: end;
  padding: 10px 0 10px 10px;
  font-size: 50px;
  letter-spacing: 0.6rem;
  background-color: #ffe600;
  margin-bottom: 20px;
}
.title_sp-only {
  display: none;
}

@media (max-width: 960px) {
  .nav-wrapper {
    background-image: url(../img/link_sp_hp.jpg);
    background-position: left top;
    height: 90vh;
  }
  h2 {
    top: 280px;
    right: 20px;
  }
  h2 p {
    font-size: 1.875rem;
  }
  .title_sp-only {
    display: block;
  }
  .title_pc-only {
    display: none;
  }
}

/* ======前へ、次へボタン====== */
.back-button_bg {
  background-image: url(../img/next_erotics.jpg);
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
  height: 200px;
  transition: transform 0.6s ease;
  width: 100%;
}
.next-button_bg {
  background-image: url(../img/next_shares.jpg);
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
  height: 200px;
  transition: transform 0.6s ease;
  width: 100%;
}