:root {
    /* ===== Brand Colors ===== */
    --color-red:   #ff0029; /* 鮮やかな赤 */
    --color-blue:  #223171; /* 深めの青 */
    --color-yellow:#fff100; /* 明るい黄色 */

    /* ===== Neutral / Gray Scale ===== */
    --color-black1: #222222; /* 黒1*/
    --color-black2: #333333; /* 黒2 */
    --color-white:white; /* 白 */
}

body{
	font-family: 
    "Noto Sans JP",
    "Hiragino Kaku Gothic ProN",
    "Hiragino Sans",
    "Meiryo", Verdana , "Roboto" ,
    sans-serif,
    "Helvetica Neue", Helvetica ,
    Arial;
  overflow-x: hidden;
}

main{
  background-image: url("../img/bg.jpg");
  background-repeat: repeat;        /* ← タイル状に繰り返す */
  background-attachment: fixed;     /* ← スクロールしても固定 */  
}

a {
    text-decoration: none;
    color: inherit;
}

ul{ list-style-type: none;}

img {
    max-width: 100%;
    height: auto;
    vertical-align: middle;
}

p,li{
  color: var(--color-black1);
}

/* 共通セクションスタイル */
.section {
    padding: 40px 20px;
    margin-bottom: 40px;
}
.section h2 {
    text-align: center;
    margin-bottom: 40px;
}

.logo{
    width: 95%;
    margin: -2rem auto auto auto;
    display: block;
    max-width: 680px;
}

.h2_img{
    height: 55px;
  display: block;
  margin: auto;
}

/* ヘッダー */



.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px; /* サイトの最大幅を設定 */
    margin: 0 auto;
    position: absolute;
}

html {
  scroll-behavior: smooth;
}

/* 右上に固定配置（必要に応じて位置調整） */
.global-nav{
  position: fixed;
  top: 16px;
  right: 16px;
  z-index: 1000;
}

/* ハンバーガー本体 */
.hamburger-menu{
    width: 42px; height: 42px;
    display: grid;  
    place-items: center;
    cursor: pointer;
    background-color: unset;
    position: fixed; 
    top: 10px;       
    right: 10px;  
    z-index: 1000;   
    mix-blend-mode: difference;
}
.hamburger-menu span {
  width: 40px;
  height: 3px;
    background: gray;
  display: block;
    transition:
    transform 0.35s cubic-bezier(0.77, 0, 0.175, 1),
    opacity 0.25s ease,
    background-color 0.3s ease;
  transform-origin: center;
}

.hamburger-menu.is-open span:nth-child(1) {
  transform: translateY(14px) rotate(45deg);
}
.hamburger-menu.is-open span:nth-child(2) {
  opacity: 0;
}
.hamburger-menu.is-open span:nth-child(3) {
  transform: translateY(-14px) rotate(-45deg);
}

/* スライドパネル */
.menu-panel {

  position: fixed;                /* ← 画面基準に固定 */
  top: calc(10px + 42px + 8px);   /* ハンバーガーの top(10px) + 高さ(42px) + 余白(8px) */
  right: -50px;
  width: 180px;
  padding: 4px;
  background: var(--color-white);
  border: 1px solid var(--color-black1);
  border-radius: 5px;
  overflow: auto;
  z-index: 999;

  /* 初期状態：右外で非表示 */
  transform: translateX(120%);
  opacity: 0;
  visibility: hidden;
  transition:
    transform 0.5s ease,
    opacity 0.5s ease,
    visibility 0s 0.5s;
}

/* 開くと右→左にスライドイン */
.menu-panel.is-open {
  transform: translateX(0);
  opacity: 0.8;
  visibility: visible;
  transition:
    transform 0.5s ease,
    opacity 0.5s ease,
    visibility 0s;
}



/* リスト */
.menu-panel ul{
  list-style: none;
  margin: 0; padding: 8px;
  display: flex; flex-direction: column; gap: 6px;
}
.menu-panel a{
  display: block;
  padding: 10px 12px;
  text-decoration: none;
  color: var(--color-black1);
  font-weight: 600;
}
/* ホバーで背景色変更（黄を使用） */
.menu-panel a:hover,
.menu-panel a:focus{
  background: var(--color-yellow, #fff100);
  outline: none;
}

/* アニメ苦手設定の配慮 */
@media (prefers-reduced-motion: reduce){
  .menu-panel{ transition: none; }
  .hamburger-menu span{ transition: none; }
}


/* トップ画像セクション */

.hero-image {
  display: flex;
  margin: auto;
  align-items: center;
  justify-content: center;
  background: linear-gradient(
      to bottom,
      var(--color-black1) 0%,
      rgba(34, 34, 34, 1) 85%,
      rgba(34, 34, 34, 0) 100%
  );
  overflow: hidden;
}

.hero-image img {
    width: 140%;
    max-width: 1400px;
}

.wide-banner {
  position: relative;
  width: 100%;
  background-color: var(--color-yellow);
  box-sizing: border-box;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px 0;
  overflow: hidden;
  margin: 20px 0 0 0;
}

.wide-banner::after, 
.wide-banner::before{
  content: "";
  position: absolute;
  height: 4px;
  width: 100%;
  background-color: var(--color-black1, #222);
}
.wide-banner::before {
  top: 6px;
}
.wide-banner::after {
  bottom: 6px;
}


/* 画像（中央配置） */
.banner-image {
  max-width: 600px;
  height: auto;
  display: block;
  z-index: 1;
  width: 95%;
}


/* セクション1: 書影 */
.book-cover-list {
    display: flex;
    justify-content: center;
    gap: 40px;
    text-align: center;
}
.book-item {
    max-width: 240px;
}
.book-actions {
    margin-top: 15px;
    display: flex;
    justify-content: center;
    flex-direction: column;
    gap: 10px;
}

.button-purchase {
  background-color: var(--color-red, #ff0029);
  align-items: center;
  font-size: 1.25rem;
  color: white;
  border-radius: 40px;
  border: none;
  padding: 10px 24px;
  cursor: pointer;
  width: 200px;
  height: 40px;
  margin: auto;
  display: flex;
  text-align: center;
  justify-content: center;
  transition: opacity 0.3s ease, filter 0.3s ease;
}

/* ホバー時：少し薄く（自然な明るさ変化） */
.button-purchase:hover {
  opacity: 0.7; /* または brightness(0.9) にしてもOK */
}



.button-detail {
    width: 140px;
    height: 30px;
  background: var(--color-blue); 
  color: var(--color-white);  
  border: none;
  border-radius: 9999px;            
  display: inline-flex;             
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;              
  cursor: pointer;
  text-decoration: none;
	margin: auto;
  transition: background-color 0.25s ease;
}

.button-detail:hover {
   background-color: color-mix(in srgb, var(--color-blue, #223171) 80%, white 20%);
}

/* セクション2: 書籍の特徴 */

.features-section {
  position: relative;
  text-align: center;
  padding: 4rem 1rem;
    max-width: 970px;
    margin: auto;
}

/* セクションタイトル */
.features-section h2 {
  color: var(--color-blue);
  font-size: 2rem;
  margin-bottom: 1rem;
}

/* リード文 */
.lead {
  max-width: 940px;
  margin: 0 auto 2rem;
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--color-black2);
  font-size: 1.5rem;
  line-height: 1.5;
  font-weight: 700;
}

/* 六角形カード全体（縦並び） */
.feature-cards-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2.5rem;
  position: relative;
  z-index: 2;
}

/* 六角形カード本体 */
.feature-card {
  position: relative;
    width: clamp(220px, 75%, 560px);
  background: var(--color-black2);
  color: var(--color-white);
  clip-path: polygon(
    6% 0%, 94% 0%, 100% 50%, 94% 100%, 6% 100%, 0% 50%
  );
    padding: 1rem 3rem;
  box-sizing: border-box;
}

/* 配置の違い */
.feature-card.left { align-self: flex-start; }
.feature-card.right { align-self: flex-end; }
.feature-card.center { align-self: center; }

/* 見出し（黄色・中央寄せ） */
.feature-card h3 {
  color: var(--color-yellow);
  text-align: center;
  margin-bottom: 5px;
  font-size: 1.4rem;
    font-feature-settings: "palt" 1;
}

/* 本文（白・両端揃え） */
.feature-card p {
  text-align: justify;
  line-height: 1.7;
  margin: 0;
  color: var(--color-white)
}

/* イラスト配置 */
.feature-illustrations {
  position: relative;
}

.illu {
  position: absolute;
  max-width: 245px;
  height: auto;
  z-index: 0;
  animation: floatXY 6s ease-in-out infinite;
}

@keyframes floatXY {
  0%   { transform: translate(0, 0); }
  25%  { transform: translate(3px, -8px); }
  50%  { transform: translate(0, -12px); }
  75%  { transform: translate(-3px, -8px); }
  100% { transform: translate(0, 0); }
}

.illu:nth-of-type(2) {
  animation-delay: 1.5s;
}

.illu1 {
  top: -6rem;
  right: -27rem;
}

.illu2 {
    bottom: -15px;
    left: -45px;
}




.feature-card h3 {
font-size: 1.25rem;
}

.feature-card p {
font-size: 0.825rem;
}


/* セクション3: ポイント */
.points-section {
  text-align: center;
  padding: 3rem 0;                 /* 横は0にして全幅を確保 */
}

.point-list {
  display: flex;
  flex-direction: column;
  gap: 3rem;
  align-items: center;
}

/* 1カード */
.point-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}

.mh {
  display: flex;
  gap: 16px;
  align-items: center;
  margin-bottom: 20px;
  text-align: left;
}
.mh-r { flex-direction: row-reverse; }

.mh-img {
  width: 90px;
  border-radius: 8px;
  object-fit: cover;
  flex-shrink: 0;
}

.mh-txt { min-width: 0; }

.mh-sub {
  margin: 0 0 4px;
  font-size: 1.25rem;
  color: var(--color-black2);
  font-weight: 500;
}

.mh-ttl {
  margin: 0;
  color: var(--color-blue);
  font-size: 2.25rem;
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -0.5px;
  font-feature-settings: "palt" 1;
}

ruby rt {
  font-size: 0.75rem;
  color: currentColor;
}


/* タイトル */
.point-title {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--color-blue, #223171);
}

/* 画像エリア：とにかく横幅を使う */
.point-media {
  position: relative;
  width: 90%;
  max-width: 1200px;               
  aspect-ratio: 1.414 / 1;
  margin: 0 auto;
  overflow: visible;    
  border: 1px solid var(--color-black1);
  box-sizing: border-box;
}

/* ページ画像：はみ出しなく全体にフィット */
.book-page {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;                 /* 余白なく見せたい場合は cover。余白OKなら contain に */
  opacity: 0;
  transition: opacity 0.4s ease;
}
.book-page.active {
  opacity: 1;
  z-index: 1;
}

/* 1. ボタン本体の基本設定とテキストの非表示 */
.nav-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 56px;
  height: 56px;
  display: grid;
  place-items: center;

  line-height: 1;
  color: var(--color-white); /* 矢印の線色 */
  background: var(--color-blue);
  
  border-radius: 50%;
  cursor: pointer;
  z-index: 2;
  left: auto;
  right: auto;
  transition: transform 0.25s ease, filter 0.25s ease;
}

/* 2. ホバー時 */
.nav-btn:hover {
  transform: translateY(-50%) scale(1.1);
  filter: brightness(1.1);
}

/* 3. 左右のボタン配置 */
.prev-btn { left: -32px; }
.next-btn { right: -32px; }


/* 4. 矢印（擬似要素）の共通スタイル */
.nav-btn::after {
  content: "";
  position: absolute;
  top: 50%;
  width: 18px;
  height: 18px;
  border-top: 3px solid currentColor;
  border-right: 3px solid currentColor;
  border-top-right-radius: 2px; /* 線の先端を丸く見せる */
}

.nav-btn.next-btn::after {
  transform: translate(-50%, -50%) rotate(45deg); 
  left: 40%;
}

.nav-btn.prev-btn::after {
  transform: translate(-50%, -50%) rotate(-135deg); 
  left: 60%;
}


/* 説明文 */
.point-description {
    margin: 1rem;
    color: var(--color-black1);
    line-height: 1.5;
    font-size: 1rem;
    font-weight: 600;
}

/* セクション4: 全巻リスト */

.book-title{
  color: var(--color-black1);
  font-size: 1.75rem;
}

.book-text{
  font-size: 0.75rem;
  color: var(--color-black2);
  margin-top: 5px;
  letter-spacing: -0.5px;
  font-feature-settings: "palt" 1;
}

.book-entry {
    display: flex;
    gap: 30px;
    align-items: flex-start;
    padding: 20px;
    max-width: 720px;
    margin: 0 auto 30px;
}
.book-cover-area {
    text-align: center;
}
.book-cover-img {
    border: 1px solid var(--color-black1);
    transition: opacity 0.3s ease; /* ← なめらかに変化させる */
}


.list-book-cover {
  width: 230px;
  height: auto;
  margin-bottom: 10px;
  border: 1px solid var(--color-black1, #222);
  transition: opacity 0.3s ease; /* ← なめらかに変化させる */
}

/* ホバー時：少し薄く（80%の不透明度） */
.book-cover-img:hover,
.list-book-cover:hover {
  opacity: 0.7;
}
.upcoming-card_last {
    display: unset;
}


.book-info-area {
    flex: 1;
}
.sales-links {
    margin-top: 15px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    width: 100%;
    justify-content: center;
}
.sales-link {
  line-height: 1.125;
  padding: 5px 10px;
  border: none;
  border-radius: 20px;
  font-size: 0.85rem;
  width: 200px;
  height: 40px;
  color: var(--color-white, #fff);
  background-color: var(--color-red, #ff0029);
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  text-align: center;
  transition: background-color 0.25s ease;
}

/* ホバー時：赤を少し薄く（明るく） */
.sales-link:hover {
  background-color: color-mix(in srgb, var(--color-red, #ff0029) 80%, white 20%);
}

.upcoming-section {
  position: relative;
  padding: 4rem 1rem 0rem;
  text-align: center;
}

/* カードレイアウト：PCは2列、2行目は中央揃え */
.upcoming-cards-container {
    display: flex;
    gap: 24px;
    max-width: 750px;
    margin: 2rem auto 1rem;
    position: relative;
    flex-wrap: wrap;
    z-index: 2;
}

.upcoming-card {
  background: var(--color-white, #fff);
  color: var(--color-black2, #333);
  border: 1px solid var(--color-black1, #222);
  border-radius: 8px;
  padding: 8px 10px;
  text-align: left;
  max-width: 360px;
  margin: auto;
  width: 85%;
}

.upcoming-card.center {
  grid-column: 1 / -1;         
  place-self: center;            /* 中央寄せ */
  max-width: 520px;             
}

.upcoming-card_last{
  display: flex;
    margin: auto;
    gap: 20px;
    align-items: center;
}

.upcoming_img{
  width: 160px;
  justify-content: center;
}

.upcoming_img img{
  width: 100%;
}


/* 小さめの発売予定テキスト */
.release-date {
  font-size: 0.9rem;
  color: var(--color-blue);
  letter-spacing: 0.02em;
  font-weight: 700;
}

/* 長い横線 */
.divider {
  border: none;
  height: 1px;
  background: var(--color-black1);
  margin: 0 0 5px;
  color: var(--color-white);
  font-size: 2rem;
  text-align: center;
  justify-content: center;
  display: flex;
}
.divider span{
  font-size: 4px;
}


/* 巻タイトル行 */
.volume {
  display: flex;
  align-items: center;
  gap: 10px;
  line-height: 1.6;
}

/* 赤い座布団（巻数） */
.badge-red {
  display: inline-block;
  background: var(--color-red);
  color: var(--color-white);
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 700;
    font-size: 0.75rem;
  white-space: nowrap;
}

/* 巻タイトル（本文は左揃え＋両端揃え指定） */
.title {
  color: var(--color-black2, #333);
  text-align: justify;
font-size: 1.125rem;
font-weight: 800;
}

/* 背面の青い六角形バッジ（全9巻） */
.series-badge {
    position: relative;
    height: 100px;
    margin-top: -20px;
  margin-bottom: 8px;
  z-index: 1;
}

.series-hex {
  width: 180px;
  aspect-ratio: 2 / 1.732; /* 正六角形の比率（横向き用） */
  background: var(--color-blue, #223171);
  margin: 20px auto;

  /* 横向きの正六角形 */
  clip-path: polygon(
    25% 0%,
    75% 0%,
    100% 50%,
    75% 100%,
    25% 100%,
    0% 50%
  );
}


/* 注釈 */
.note {
  font-size: 0.625rem;
  color: var(--color-black2);
  margin: 0.5rem auto 1.5rem;
  letter-spacing: -1.25px;
}

/* 末尾イラスト */
.section-btm-illust img {
  max-width: min(680px, 90%);
  height: auto;
  display: block;
  margin: 0.5rem auto 0;
}




/* 追従するボタン（固定表示） */
.js-float-main {
    position: fixed;
    right: 20px;
    bottom: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transform: translateY(20px);
   transition: opacity 0.3s ease, transform 0.3s ease;
}

/* 表示状態 */
.js-float-main.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.floating-button {
    display: block;
    padding: 15px;
    margin-top: 10px;
    text-align: center;
    font-weight: bold;
    color: var(--color-white);
}
.to-top-button {
    width: 100px;
    height: 80px;
}

.purchase-button {
  width: 120px;
  aspect-ratio: 1.732 / 2;
  background: var(--color-black1);
  color: var(--color-black1);
  position: relative;
  margin: 20px;
  clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  line-height: 1.25;
  border: none;
  cursor: pointer;
  overflow: hidden;
  transition:
    transform 0.1s cubic-bezier(0.4, 0, 0.2, 1),
    box-shadow 0.2s ease,
    filter 0.2s ease,
    background-color 0.35s ease,
    color 0.35s ease;
}

.purchase-button::before {
  content: "";
  position: absolute;
  width: 85%;
  height: 85%;
  background-color: var(--color-yellow);
  color: var(--color-black1);
  z-index: -100;
  clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
  transform: scale(1.1);
  transition:
    transform 0.1s cubic-bezier(0.4, 0, 0.2, 1),
    filter 0.2s ease,
    background-color 0.35s ease,
    color 0.35s ease;
}

.purchase-button p{
  color: var(--color-black1, #222);
}

.purchase-button.hover-sharp:hover {
  transform: scale(1.05) translateY(-3px);
  filter: brightness(1.08);
  background: var(--color-yellow);
  color: var(--color-white);
}

.purchase-button.hover-sharp:hover::before {
  transform: scale(1.05) translateY(1px);
  background: var(--color-red);
  filter: brightness(1.08);
}

.purchase-button:hover p{
  color: var(--color-white);
}


/* 全体のレイアウト */
.social-share-buttons {
  text-align: center;
  margin-top: 20px;
  padding: 20px 0;
  display: flex;
  gap: 20px;
  justify-content: center;
}

/* アイコン横並び */
.social-icons {
  display: flex;
  justify-content: center;
  gap: 16px; /* アイコン間の間隔 */
}

/* 丸いアイコン共通設定 */
.share-button img {
  width: 48px;
  height: 48px;
  border-radius: 50%;          /* 丸くする */
  object-fit: cover;
  transition: opacity 0.3s ease;
}

/* ホバーで少し薄く */
.share-button:hover img {
  opacity: 0.7;
}

/* テキスト部分 */
.share-text {
  font-size: 0.825rem;
  color: var(--color-blue);
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 6px; 
  font-weight: 600;
}

/* 「シェア」アイコン（小さめ） */
.share-icon {
  width: 18px;
  height: 18px;
  vertical-align: middle;
}


/* フッター */
.site-footer {
    padding: 20px;
    text-align: center;
}

.decor-band {
  position: relative;
  width: 100%;
  height: 20px; /* 帯の太さ */
  overflow: hidden;
  background: #fff100;         /* 地色：黄色 */
  z-index: 1;
  pointer-events: none;
}

/* 左上がり（右下へ傾く） */
.decor-band.left {
  transform: rotate(-2deg);
}

/* 右上がり（左下へ傾く） */
.decor-band.right {
  transform: rotate(2deg);
}

.decor-track {
  position: absolute;
  top: 0;
  left: 0;
  display: flex;
  animation: scroll-left 20s linear infinite;
}

.decor-track img {
  height: 20px;
  width: auto;
max-width: fit-content;
}

#index-footer {
    background: #fff;
    padding: 60px 0px 30px 0px;
    text-align: center;
}

.infoLINK {
    color: #5d5d5d;
    text-align: center;
    text-decoration: underline;
    margin-bottom: 10px;
    font-size: 0.75rem;
}


#shogakukan {
    padding: 10px;
}

#shogakukan a {
    color: #5d5d5d;
    padding: 4px 6px;
    font-size: 0.825rem;
    font-weight: 400;
    line-height: 1;
    text-decoration: none;
    border: 1px solid #5d5d5d;
}
.copy {
    color: #5d5d5d;
font-size: 0.625rem;
    line-height: 1.5;
        font-family: 'Noto Sans JP';
}

.js-scroll {
  opacity: 0;
  transition: opacity 0.8s, transform 0.8s;
}


/* --- 初期位置の定義 --- */
.js-scroll[data-animation="up"] {
  transform: translateY(30px);
}

/* --- 表示時の状態 (アニメーション完了) --- */
.js-scroll.is-active {
  opacity: 1;
  transform: translate(0, 0);
}

/* --- メイン画像用の特別なアニメーション --- */
.js-scroll[data-animation="zoom"] {
  transform: scale(0.95);
}

.js-scroll[data-animation="zoom"].is-active {
  opacity: 1;
  transform: scale(1);
  /* 重厚感を出すため、時間を長く、緩急をつける */
  transition-duration: 1.5s;
  transition-timing-function: cubic-bezier(0.25, 0.46, 0.45, 0.94);
}



/* 横方向スクロールアニメーション */
@keyframes scroll-left {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(-50%);
  }
}

	/* 全体
	--------------------------------- */	
	.PC{
		display: block;
	}
	.SP{
		display: none;
	}



/* =======================================
   レスポンシブ対応 (Max-width: 767px)
   ======================================= */
@media (max-width: 767px) {

  .mh {
     margin-bottom: unset;
  }

    .mh-img { width: 80px; }


    /* --- 共通設定 --- */
    .section {
        padding: 40px 10px;
        margin-bottom: 20px;
    }
    .section h2 {
        margin-bottom: 30px;
        font-size: 1.5em; /* タイトルを小さく */
    }

    .logo {
        margin: -1rem auto auto auto;}

    .mh-ttl {
        font-size: 1.75rem;
    }

    .h2_img {
        height: 40px;
    }
    .lead {
        max-width: 700px;
        margin: 0 auto;
        font-size: 1rem;
    }

    /* --- セクション 1: 書影 --- */
    .book-cover-list {
        gap: 20px;
    }
    .book-item {
        max-width: 200px;
        width: 45%;
    }


    .button-detail {
width: 140px;
        margin: auto;
    }
    /* --- セクション 2: 書籍の特徴 --- */


    .button-purchase {
        width: 100%;
    }


    .upcoming-card {
        width: 95%;
        max-width: unset;
    }

    /* 配置の違い */
    .feature-card.left,
    .feature-card.right,
    .feature-card.center
    { align-self: unset; }

    .feature-cards-container {
        flex-direction: column; /* 縦並びにする */
        gap: 15px;
    }
    .feature-card {
        max-width: 100%;
        padding: 1rem 2rem;
    }
    .feature-illustrations {
        display: flex;
        justify-content: space-around;
    }

  .feature-card { align-self: center;        
    width: 100%; }
  .illu1, .illu2 { position: static; display: block; margin: 1rem auto; }

    /* --- セクション 3: ポイント --- */
    .point-item {
        flex-direction: column; /* 縦並びにする */
        text-align: center;
        gap: 20px;
    }
    .point-media {
        gap: 5px;
        flex: auto;
    }
  .point-description {
    font-size: 0.75rem;
  }

    .prev-btn { left: -30px; }
    .next-btn { right: -30px; }


    .nav-btn {
font-size: 0.75rem;
        width: 40px;
        height: 40px;
    }

    /* --- セクション 4: 全巻リスト --- */
    .book-entry {
        flex-direction: column;
        gap: 15px;
        align-items: center;
        max-width: 100%;
        text-align: center;
      padding: 20px 0;
    }
    .book-cover-area {
        flex: none;
        width: 200px;
    }
    .book-title {
        font-size: 1.2em;
    }
    .sales-link {
        width: 45%;
        font-size: 0.75rem;
    }
    .illu {
      max-width: 150px;
    }
    /* --- セクション 5: 今後のラインナップ --- */

    .upcoming-cards-container {
        grid-template-columns: 1fr;
    }
    .upcoming-card.center {
        grid-column: auto;
        max-width: none;
        place-self: unset;
    }
    .series-badge {
        height: 80px;
        margin-top: -20px;
    }
    .series-hex {
        padding: 12px 24px;
    }

    .js-float-main {
      position: fixed;
      right: 0px;
      bottom: 0px;
    }
    .title {
      font-size: 1rem;
    }

    .upcoming-cards-container {
      gap: 15px;
    }

    .purchase-button {
      width: 95px;
      aspect-ratio: 1.732 / 2;
      position: relative;
      margin: 10px;
      font-size: 1.5rem;
    }
    .upcoming-card_last {
      flex-wrap: wrap;
      justify-content: center;
      width: 100%;
    }
    .upcoming_img {
      width: 110px;
    }

.to-top-button {
    width: 80px;
    height: 65px;
}

.mh-sub {
  font-size: 0.875rem;
}

	/* 全体
	--------------------------------- */	
	.PC{
		display: none;
	}
	.SP{
		display: block;
	}

}