/* ============================================================
   mobile.css — スマートフォン向けレスポンシブスタイル
   対象：index.html / base.css を補完するメディアクエリ集
   読み込み順：base.css の後に <link rel="stylesheet" href="mobile.css"> で追加
   ============================================================ */

/* ============================================================
   1. タブレット幅（〜900px）
   ============================================================ */
@media (max-width: 900px) {

  /* ----- ヘッダー ナビ ----- */
  .header-nav {
    gap: 0;
  }
  .header-nav li a {
    padding: 6px 10px;
    font-size: 13px;
  }

  /* ----- HERO ----- */
  .hero-inner {
    flex-direction: column;
    gap: 24px;
    padding: 40px 20px;
    text-align: center;
  }
  .hero-book {
    width: 180px;
    margin: 0 auto;
  }
  .hero-stats {
    justify-content: center;
  }
  .hero-buttons {
    justify-content: center;
  }

  /* ----- BOOK DETAIL ----- */
  #book .book-layout {
    flex-direction: column;
    gap: 30px;
  }
  .book-cover {
    width: 180px;
    margin: 0 auto;
  }
  .book-sideimg {
    display: none; /* 小さい画面ではサイド装飾画像を非表示 */
  }
  .buy-section {
    margin-left: 0;
  }

  /* ----- SPECIAL ----- */
  #investgate .section-inner {
    flex-direction: column;
  }
  .special-content {
    width: 100%;
    flex-direction: column;
    gap: 40px;
  }
  .special-content a {
    width: 100%;
  }
  .special-content .special-card2,
  .special-content .special-card3 {
    position: static;
    top: auto;
    left: auto;
  }

  /* ----- AUTHOR ----- */
  .author-grid-wf2 {
    grid-template-columns: 1fr;
  }
  .author-title-box,
  .author-stats-box,
  .author-profile-box,
  .author-bio-box,
  .author-interview-box {
    grid-column: auto;
    grid-row: auto;
    width: 100%;
  }
  .author-profile-box {
    width: 100%;
  }
  .author-stats-row {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
  }
  .author-stat {
    min-width: 140px;
    padding-top: 50px;
  }
  .author-interview-box {
    justify-content: center;
  }
  .interview-link {
    max-width: 200px;
  }

  /* ----- FOOTER ----- */
  .footer-top {
    flex-direction: column;
    align-items: flex-start;
  }
  .footer-buy {
    text-align: left;
  }
}


/* ============================================================
   2. スマートフォン幅（〜768px）
   ============================================================ */
@media (max-width: 768px) {

  /* ----- ヘッダー ----- */
  .header-inner {
    height: auto;
    padding: 10px 16px;
    flex-wrap: wrap;
    gap: 8px;
  }
  .header-logo img {
    width: 120px;
    height: auto;
  }
  /* ナビをスクロール可能な横並びに */
  nav {
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  .header-nav {
    display: flex;
    flex-wrap: nowrap;
    gap: 0;
    width: max-content;
    padding-bottom: 4px;
    justify-content: space-between;
  }
  .header-nav li a {
    padding: 6px 9px;
    font-size: 12px;
  }
  .header-nav li a .nav-en {
    font-size: 8px;
  }
  .header-buy-btn {
    padding: 6px 10px !important;
    font-size: 12px !important;
  }

  /* ----- SECTION 共通 ----- */
  .section {
    padding: 48px 16px;
  }
  .section-title {
    font-size: clamp(18px, 7vw, 30px);
  }
  .section-header {
    margin: 0 0 30px;
  }

  /* ----- HERO ----- */
  .hero-inner {
    padding: 32px 16px 40px;
    gap: 20px;
  }
  .hero-inner > img {
    width: 100%;
    height: auto;
    display: block;
  }
  .hero-book {
    width: 150px;
  }
  .hero-title {
    font-size: clamp(20px, 6vw, 30px);
  }
  .hero-stats {
    gap: 10px;
    margin: 20px 0;
  }
  .hero-stat {
    padding: 8px 12px;
    flex: 1 1 calc(50% - 10px);
    min-width: 120px;
  }
  .hero-stat .num {
    font-size: 26px;
  }

  /* ----- STATS BAND ----- */
  .stats-band {
    padding: 60px 16px;
  }
  .stats-band-inner {
    gap: 28px;
    justify-content: space-between;
  }
  .stat-item {
    flex: 1 1 calc(50% - 14px);
    min-width: 130px;
  }
  .stat-item .s-num {
    font-size: clamp(40px, 10vw, 72px);
  }
  .stats-title {
    font-size: clamp(16px, 4.5vw, 28px);
    gap: 4px;
  }
  .stats-title b {
    font-size: clamp(20px, 6vw, 42px);
  }
  .stats-title span {
    font-size: clamp(11px, 3vw, 18px);
  }

  /* ----- BOOK DETAIL ----- */
  #book .book-layout {
    flex-direction: column;
    gap: 24px;
  }
  .book-cover {
    width: 300px;
    margin: 0 auto;
  }
  .book-cover img{
    width: 180px;
  }
  .book-title-main {
    font-size: clamp(17px, 4.5vw, 26px);
    text-align: center;
  }
  .book-catch{
    text-align: center;
    margin-bottom: 0;
  }
  .book-desc {
    font-size: 14px;
  }
  .book-meta {
    margin-top: .5em;
    text-align: center;
  }
  .book-meta li {
    flex: 1 0 100%;
    padding: 6px 10px;
  }
  .buy-section {
    margin: 24px 0 0;
    padding: 16px;
  }
  .buy-links {
    flex-direction: column;
    align-items: stretch;
  }
  a.buy-link {
    width: 100%;
  }
  .book-info{
    margin-top:2em;
  }


  /* ----- COLUMN ----- */
  #column .col-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .col-card {
    border-radius: 8px;
  }

  /* ----- SPECIAL / 調査報告 ----- */
  .special-content {
    width: 100%;
    gap: 30px;
  }
  .special-content a {
    width: 100%;
    box-shadow: 8px 8px 0 0 rgb(255, 255, 0);
  }
  .special-content .sp-title {
    font-size: 16px;
    top: 50px;
    padding: 0 0.8em 0 40px;
  }
  .special-content .sp-cardhead {
    height: 160px;
    padding-top: 30px;
  }
  .special-card1,
  .special-card2,
  .special-card3 {
    background-size: 90px auto;
  }

  /* ----- AUTHOR ----- */
  .author-stat-num {
    font-size: 40px;
  }
  .author-stat-unit {
    font-size: 14px;
  }
  .author-stat-label {
    font-size: 11px;
  }
  .author-bio-text {
    padding:0 1.5em;
  }
  .author-name {
    font-size: 18px;
    letter-spacing: 3px;
  }

  /* ----- SITE FOOTER ----- */
  .footer-top {
    flex-direction: column;
    gap: 20px;
  }
  .site-footer-inner {
    padding: 0 4px;
    flex-direction: column;
    align-items: center;
  }
  #site-footer {
    padding: 40px 16px 24px;
  }
  .site-footer-inner .buy-section{
    margin: 2em auto;
    width:90%;
  }
  .site-footer-inner .buy-section .buy-link{
    padding:20px;
    width:100%;
  }
  .site-footer-inner .buy-section h5{
    left:25%;
  }
}


/* ============================================================
   3. 小型スマートフォン幅（〜480px）
   ============================================================ */
@media (max-width: 480px) {

  /* ----- ヘッダー ----- */
  .header-inner {
    padding: 8px 12px;
  }
  .header-logo img {
    width: 100px;
  }

  /* ----- HERO ----- */
  .hero-inner {
    padding: 0
  }
  .hero-book {
    width: 130px;
  }
  .btn-amazon {
    font-size: 15px;
    padding: 10px 18px;
    width: 100%;
    justify-content: center;
  }

  /* ----- STATS BAND ----- */
  .stats-band {
    padding: 48px 12px;
  }
  .stat-item {
    flex: 1 1 45%; /* 1列表示 */
  }
  .stat-item .s-num {
    font-size: clamp(48px, 14vw, 80px);
  }

  /* ----- SECTION 共通 ----- */
  .section {
    padding: 40px 12px;
  }

  /* ----- BOOK DETAIL ----- */
  .book-desc {
    font-size: 16px;
    width: 90%;
    margin: 0 auto;
  }
  .book-list-wrap{
   width: 90%;
   margin:2em auto;
   text-align: left;
  }
  .book-list {
    font-size: 12px;
  }
  .book-list b{
    text-align: left;
  }
  .book-list-wrap h4{
    left:calc(50% - 50px);
  }
  .buy-section h4 {
   left:calc(50% - 100px);    
  }

  /* ----- COLUMN ----- */
  .col-card .card-title {
    font-size: 14px;
  }

  /* ----- AUTHOR ----- */
  .author-stats-row {
    /* flex-direction: column; */
    align-items: center;
    width: 100%;
  }
  .author-stat {
    width: 45%;
    max-width: 260px;
    background-size: 80px;
  }
  .author-stat-num {
    font-size: 48px;
  }
  .author-photo-area {
    width: 70%;
    margin:1em auto;
  }

  /* ----- SPECIAL ----- */
  .special-content .sp-title {
    font-size: 15px;
    padding: 0 0.6em 0 35px;
    top: 45px;
  }
  .special-content .sp-cardhead {
    height: 140px;
    padding-top: 24px;
  }
  .special-card1,
  .special-card2,
  .special-card3 {
    background-size: 75px auto;
  }

  /* スクロールバーを非表示（ヘッダーナビ横スクロール） */
  nav::-webkit-scrollbar {
    display: none;
  }
  nav {
    scrollbar-width: none;
    display: flex;
    justify-content: space-around;
  }
}