/* ============================================================
   本格ミステリ・ハズレ回避ガイド — Design System
   コンセプト: ホームズ221Bの書斎(深緑+真鍮+木目)
   3テーマを切替できるように --theme-* を data-theme で上書き
   ============================================================ */

/* ---------- Tokens (default = study/書斎) ---------- */
:root,
[data-theme="study"] {
  --bg:        #fafaf7;   /* ほぼ白(ごく僅かにウォーム) */
  --bg-deep:   #f3f2ec;   /* ナビ・補助エリア用の薄いウォームグレー */
  --paper:     #ffffff;   /* 主役のページ:純白 */
  --ink:       #1a1f1c;   /* 本文の黒 */
  --sub:       #5b6360;
  --muted:     #9aa09c;

  --line:      #e3e1d6;   /* ニュートラル寄りの罫線 */
  --line-soft: #ededea;

  --primary:    #0f3528;  /* British Racing Green:濃く絞る */
  --primary-2:  #1c4a3a;
  --primary-3:  #07241a;
  --primary-ink:#e7eee0;
  --brass:      #a8761f;  /* 真鍮:濃く・彩度高め */
  --brass-2:    #d29f3a;  /* ハイライトのシャンパンゴールド */
  --brass-3:    #f0d896;
  --brass-deep: #6e4c12;
  --accent-warm:#7a2820;
  --accent:     var(--primary);  /* 旧テーマからの互換エイリアス */
  --card:       var(--paper);    /* 同上 */

  --shadow-soft: 0 1px 0 #d6c9aa, 0 12px 28px -16px rgba(26,40,32,0.22);
  --shadow-deep: 0 1px 0 #b09773, 0 18px 40px -22px rgba(26,40,32,0.40);

  --radius: 4px;
  --radius-sm: 2px;
  --radius-lg: 10px;

  --font-mincho: "Shippori Mincho", "Hiragino Mincho ProN", "YuMincho", "Yu Mincho", "Noto Serif JP", serif;
  --font-noto-serif: "Noto Serif JP", "Hiragino Mincho ProN", serif;
  --font-gothic: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Noto Sans JP", system-ui, sans-serif;
  --font-en-serif: "Cormorant Garamond", "EB Garamond", Georgia, "Times New Roman", serif;
  --font-en-display: "Playfair Display", "Cormorant Garamond", Georgia, serif;

  --font-body: var(--font-gothic);
  --font-display: var(--font-mincho);
}

/* 案B: 書庫(赤茶+革表紙) */
[data-theme="leather"],
[data-theme="library"] {
  --bg:        #faf4e9;
  --bg-deep:   #f1e8d3;
  --paper:     #ffffff;
  --ink:       #2a1d15;
  --sub:       #6a5446;
  --muted:     #b4a48f;
  --line:      #e8d8b8;
  --line-soft: #f1e7d2;
  --primary:   #6b2520;
  --primary-2: #8a3a32;
  --primary-ink:#f1ddc7;
  --brass:     #b48140;
  --brass-2:   #d6a560;
  --accent-warm:#3b6555;
}

/* 案C: 夜の書斎(ネイビー+真鍮、ややダーク) */
[data-theme="foggy"],
[data-theme="midnight"] {
  --bg:        #1a1f2b;
  --bg-deep:   #131826;
  --paper:    #232a39;
  --ink:       #ecdfc1;
  --sub:       #b9ad8e;
  --muted:     #6f6a59;
  --line:      #3a4255;
  --line-soft: #2a3142;
  --primary:   #c9a046;
  --primary-2: #e0b85c;
  --primary-ink:#1a1f2b;
  --brass:     #c9a046;
  --brass-2:   #e0b85c;
  --accent-warm:#b87a4a;
}

/* ---------- Reset ---------- */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "palt";
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font: inherit; }

/* ---------- 紙テクスチャ(うっすら) ---------- */
body.paper-texture {
  background-image:
    radial-gradient(ellipse 1200px 600px at 30% -10%, rgba(31,59,50,0.04), transparent 60%),
    radial-gradient(ellipse 800px 400px at 110% 30%, rgba(176,138,62,0.05), transparent 60%);
}

/* ============================================================
   ヘッダー
   ============================================================ */
.site-header {
  background: var(--paper);
  color: var(--ink);
  border-bottom: 1px solid var(--line);
  position: relative;
}
.site-header::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -3px; height: 2px;
  background: linear-gradient(90deg, transparent, var(--brass-2) 30%, var(--brass-3) 50%, var(--brass-2) 70%, transparent);
  opacity: 0.55;
}
.header-inner {
  max-width: 1180px; margin: 0 auto; padding: 18px 32px;
  display: flex; align-items: center; gap: 24px;
}
.brand {
  display: flex; align-items: center; gap: 14px;
}
.brand-mark {
  width: 48px; height: 48px; border-radius: 50%;
  background: var(--primary);
  color: var(--brass-2);
  display: grid; place-items: center;
  border: 1.5px solid var(--brass);
  box-shadow: inset 0 0 0 2px var(--paper), 0 1px 2px rgba(0,0,0,0.15);
  letter-spacing: 0.02em;
}
.brand-text h1 {
  margin: 0; font-family: var(--font-display);
  font-size: 19px; letter-spacing: 0.04em; font-weight: 600;
}
.brand-text .tag {
  font-size: 11px; color: var(--sub); letter-spacing: 0.18em;
  margin-top: 2px; font-family: var(--font-en-serif); font-style: italic;
}
.header-search {
  margin-left: auto; flex: 0 1 320px;
  position: relative;
}
.header-search input {
  width: 100%; padding: 9px 12px 9px 36px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
  font-family: inherit; font-size: 13px;
  border-radius: 999px;
  transition: border-color .15s, box-shadow .15s;
}
.header-search input:focus {
  outline: none; border-color: var(--primary);
  box-shadow: 0 0 0 3px color-mix(in oklab, var(--primary) 18%, transparent);
}
.header-search .glass {
  position: absolute; left: 12px; top: 50%; transform: translateY(-50%);
  width: 16px; height: 16px;
  border: 1.5px solid var(--sub); border-radius: 50%;
}
.header-search .glass::after {
  content: ""; position: absolute; left: 12px; top: 12px;
  width: 8px; height: 1.5px; background: var(--sub);
  transform: rotate(45deg); transform-origin: 0 50%;
}

/* ナビ */
.site-nav {
  background: var(--bg-deep);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 1180px; margin: 0 auto; padding: 0 28px;
  display: flex; gap: 4px; align-items: stretch;
}
.site-nav a {
  position: relative;
  padding: 14px 18px; font-size: 13.5px; color: var(--sub);
  letter-spacing: 0.04em;
  font-family: var(--font-display);
  transition: color .15s;
}
.site-nav a + a::before {
  content: "·"; position: absolute; left: -2px; top: 50%; transform: translateY(-50%);
  color: var(--line); font-size: 14px;
}
.site-nav a:hover, .site-nav a.is-active {
  color: var(--primary);
}
.site-nav a.is-active::after {
  content: ""; position: absolute; left: 18px; right: 18px; bottom: 6px; height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

/* ============================================================
   レイアウト
   ============================================================ */
.main {
  max-width: 1180px; margin: 0 auto; padding: 36px 32px 80px;
}
.crumbs {
  font-size: 12px; color: var(--sub); margin-bottom: 18px;
  font-family: var(--font-en-serif); letter-spacing: 0.04em;
}
.crumbs a:hover { color: var(--primary); }
.crumbs span.sep { margin: 0 8px; opacity: 0.6; }

/* セクション見出し */
.section { margin-bottom: 56px; }
.section-head {
  display: flex; align-items: baseline; gap: 16px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 10px; margin-bottom: 22px;
}
.section-head .eyebrow {
  font-family: var(--font-en-serif); font-style: italic;
  font-size: 12px; color: var(--primary); letter-spacing: 0.15em;
}
.section-head h2 {
  margin: 0; font-family: var(--font-display);
  font-size: 19px; letter-spacing: 0.05em; font-weight: 600;
}
.section-head .lede {
  font-size: 12px; color: var(--sub);
}
.section-head .more {
  margin-left: auto; font-size: 12px; color: var(--sub);
  font-family: var(--font-en-serif); letter-spacing: 0.06em;
}
.section-head .more:hover { color: var(--primary); }

/* ============================================================
   書影プレースホルダ(本物の書影が来るまでの差し込み枠)
   背景=深緑、装飾=真鍮、模様=斜めストライプ
   ============================================================ */
.cover {
  position: relative;
  background: linear-gradient(160deg, var(--primary) 0%, color-mix(in oklab, var(--primary) 85%, #000 15%) 100%);
  color: color-mix(in oklab, var(--brass-2) 80%, #fff 20%);
  border-radius: 2px;
  display: flex; flex-direction: column; justify-content: space-between;
  padding: 16px 14px;
  overflow: hidden;
  box-shadow: var(--shadow-soft);
  isolation: isolate;
}
.cover::before {
  content: "";
  position: absolute; inset: 0;
  background: repeating-linear-gradient(
    45deg,
    transparent 0 14px,
    rgba(255,255,255,0.04) 14px 15px
  );
  z-index: 0;
}
.cover::after {
  /* 真鍮の縁飾り */
  content: ""; position: absolute; inset: 8px;
  border: 1px solid color-mix(in oklab, var(--brass) 70%, transparent);
  border-radius: 1px;
  pointer-events: none;
  z-index: 0;
}
.cover > * { position: relative; z-index: 1; }
.cover .c-rune {
  font-family: var(--font-en-display);
  font-size: 11px; letter-spacing: 0.3em;
  opacity: 0.7;
  text-transform: uppercase;
}
.cover .c-title {
  font-family: var(--font-display);
  font-weight: 700; line-height: 1.4;
  font-size: 14px;
  text-shadow: 0 1px 0 rgba(0,0,0,0.2);
}
.cover .c-author {
  font-size: 10.5px; opacity: 0.78;
  font-family: var(--font-en-serif); font-style: italic;
}
.cover.tone-warm  { background: linear-gradient(160deg, #5a3525, #2c1810); }
.cover.tone-leather { background: linear-gradient(160deg, #6b2520, #2a0e0a); }
.cover.tone-classic { background: linear-gradient(160deg, #2c3e50, #14202d); }

/* placeholder ラベル(後から書影が差し込まれる前提) */
.cover[data-placeholder]::before {
  content: ""; /* override */
}
.cover .ph-tag {
  position: absolute; top: 8px; right: 8px;
  font-family: ui-monospace, "SFMono-Regular", Menlo, monospace;
  font-size: 9px; letter-spacing: 0.08em;
  color: rgba(255,255,255,0.45);
  background: rgba(0,0,0,0.25);
  padding: 2px 5px; border-radius: 2px;
  z-index: 2;
}

/* ============================================================
   ボタン / バッジ
   ============================================================ */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 14px; font-size: 12.5px;
  border: 1px solid var(--line); background: var(--paper);
  color: var(--ink); border-radius: 999px;
  cursor: pointer; transition: all .15s;
  letter-spacing: 0.02em;
}
.btn:hover {
  border-color: var(--primary); color: var(--primary);
  transform: translateY(-1px);
}
.btn.primary {
  background: var(--primary); color: #fff;
  border: 1px solid var(--primary);
  box-shadow: inset 0 0 0 1px var(--primary-2);
}
.btn.primary:hover {
  background: var(--primary-2); border-color: var(--primary-2);
  color: #fff;
}
.btn.brass {
  background: transparent; border: 1px solid var(--brass);
  color: var(--brass);
}
.btn.brass:hover { background: var(--brass); color: var(--paper); }

.badge {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 3px 9px; border-radius: 999px;
  font-size: 10.5px; letter-spacing: 0.12em;
  font-family: var(--font-en-serif);
  text-transform: uppercase;
}
.badge.oshi {
  background: var(--brass); color: var(--paper);
  font-weight: 600;
}
.badge.ai {
  background: var(--ink); color: var(--bg);
}
.badge.outline {
  background: transparent; color: var(--sub);
  border: 1px solid var(--line);
}
.badge.kana { font-family: var(--font-display); letter-spacing: 0.06em; }

/* ============================================================
   ブックカード(ホバーで関連書籍がふわっと出る)
   ============================================================ */
.book-card {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  display: grid; grid-template-columns: 88px 1fr; gap: 16px;
  cursor: pointer;
  transition: border-color .2s, transform .2s, box-shadow .2s;
}
.book-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-soft);
}
.book-card .cover {
  width: 88px; height: 124px;
  padding: 10px 9px;
}
.book-card .cover .c-title { font-size: 11px; }
.book-card .cover .c-author { font-size: 9px; }
.book-card .meta .cat {
  font-size: 10.5px; color: var(--primary);
  letter-spacing: 0.18em; font-family: var(--font-en-serif); font-style: italic;
  font-weight: 600;
}
.book-card .meta h3 {
  margin: 4px 0 2px; font-family: var(--font-display);
  font-size: 15.5px; line-height: 1.45; font-weight: 600;
}
.book-card .meta .author {
  font-size: 12px; color: var(--sub); margin-bottom: 8px;
}
.book-card .meta .push {
  font-size: 12.5px; line-height: 1.7; color: var(--ink);
  border-top: 1px dotted var(--line); padding-top: 8px;
}
.book-card .moods {
  margin-top: 8px; display: flex; flex-wrap: wrap; gap: 4px;
}
.book-card .moods span {
  font-size: 10.5px;
  color: var(--accent);
  background: rgba(20, 56, 47, 0.06);
  padding: 2px 8px; border-radius: 999px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

/* ホバーで現れる「これを読んだ人へ」ピーク */
.book-card .peek {
  position: absolute; left: 50%; bottom: -10px; transform: translate(-50%, 100%);
  width: calc(100% - 8px);
  background: var(--ink); color: var(--bg);
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 11.5px; line-height: 1.55;
  opacity: 0; pointer-events: none;
  transition: opacity .2s, transform .2s;
  z-index: 6; box-shadow: var(--shadow-deep);
}
.book-card .peek::before {
  content: ""; position: absolute; left: 50%; top: -6px; transform: translateX(-50%) rotate(45deg);
  width: 10px; height: 10px; background: var(--ink);
}
.book-card:hover .peek {
  opacity: 1; transform: translate(-50%, calc(100% + 6px));
}
.book-card .peek .peek-label {
  font-family: var(--font-en-serif); font-style: italic;
  color: var(--brass-2); letter-spacing: 0.12em;
  font-size: 10px; display: block; margin-bottom: 2px;
}

/* ============================================================
   ミニ・スピーン(背表紙風)— 横スクロール用
   ============================================================ */
.shelf {
  display: flex; gap: 14px; overflow-x: auto;
  padding: 4px 2px 18px;
  scroll-snap-type: x mandatory;
}
.shelf::-webkit-scrollbar { height: 6px; }
.shelf::-webkit-scrollbar-thumb { background: var(--line); border-radius: 3px; }

.spine {
  flex: 0 0 152px; scroll-snap-align: start;
  cursor: pointer;
}
.spine .cover {
  width: 152px; height: 220px;
  padding: 14px 12px;
}
.spine .cover .c-title { font-size: 13px; }
.spine .meta {
  margin-top: 8px;
}
.spine .meta .cat {
  font-family: var(--font-en-serif);
  font-size: 9.5px; letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 4px;
}
.spine .meta .ttl {
  font-size: 12.5px; font-family: var(--font-display); font-weight: 600;
  line-height: 1.45;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden;
}
.spine .meta .auth {
  font-size: 11px; color: var(--sub); margin-top: 2px;
}
.spine .meta .spine-moods {
  display: flex; flex-wrap: wrap; gap: 4px; margin-top: 6px;
}
.spine .meta .spine-mood {
  font-size: 10px;
  font-family: var(--font-jp);
  color: var(--accent);
  background: rgba(20, 56, 47, 0.06);
  padding: 1.5px 7px;
  border-radius: 999px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}
.spine:hover .cover { transform: translateY(-3px); transition: transform .2s; }

/* ============================================================
   フッター
   ============================================================ */
.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 48px;
  padding: 28px 32px 36px;
  text-align: center;
  color: var(--sub);
  font-size: 11.5px;
  background: var(--paper);
  position: relative;
}
.site-footer::before {
  content: ""; position: absolute; left: 0; right: 0; top: -4px; height: 3px;
  background: linear-gradient(90deg, transparent, var(--brass) 30%, var(--brass-2) 50%, var(--brass) 70%, transparent);
  opacity: 0.5;
}
.site-footer .ornament {
  font-family: var(--font-en-display);
  font-size: 14px; color: var(--brass);
  letter-spacing: 0.4em;
  margin-bottom: 6px;
}

/* ============================================================
   コモン
   ============================================================ */
.eyebrow-en {
  font-family: var(--font-en-serif); font-style: italic;
  letter-spacing: 0.18em; color: var(--brass);
  font-size: 12px; text-transform: lowercase;
}
.divider-ornament {
  display: flex; align-items: center; gap: 12px;
  color: var(--brass); font-family: var(--font-en-display);
  font-size: 14px; letter-spacing: 0.4em;
  margin: 24px 0;
}
.divider-ornament::before, .divider-ornament::after {
  content: ""; flex: 1; height: 1px; background: var(--line);
}

/* ============================================================
   レイアウトパターン (Tweaks: layout)
   ============================================================ */

/* A: 標準(現状) — そのまま */

/* B: マガジン型 — ヒーローを横長フルブレイド + 二段組ピックアップ */
[data-layout="magazine"] .hero {
  grid-template-columns: 1fr;
  padding: 56px 56px 40px;
  text-align: center;
}
[data-layout="magazine"] .hero .hero-cover {
  margin: 0 auto 18px;
}
[data-layout="magazine"] .hero-body .pull {
  border-left: none; padding: 0;
  font-size: 19px; max-width: 60ch; margin: 18px auto;
}
[data-layout="magazine"] .hero-body .summary { margin: 0 auto 18px; }
[data-layout="magazine"] .hero-actions { justify-content: center; }
[data-layout="magazine"] .path-cards { grid-template-columns: 1fr 1fr; }

/* C: コラムブック型 — メインが左 60%、サイドバー右 40% で人気記事を常時 */
[data-layout="columned"] .main { max-width: 1240px; }
[data-layout="columned"] .hero { grid-template-columns: 200px 1fr; padding: 28px; }
[data-layout="columned"] .hero .hero-cover { width: 200px; height: 290px; }
[data-layout="columned"] .hero-body h2 { font-size: 26px; }
[data-layout="columned"] .path-cards { grid-template-columns: repeat(3, 1fr); gap: 12px; }
[data-layout="columned"] .path-card { padding: 16px; }
[data-layout="columned"] .path-card h4 { font-size: 14.5px; }
[data-layout="columned"] .path-card p { font-size: 11.5px; }

/* D: ジャーナル型 — 紙の本のような中央寄せ・余白多め・装飾控えめ */
[data-layout="journal"] .main { max-width: 880px; padding-top: 56px; }
[data-layout="journal"] .hero {
  background: transparent; border: none; box-shadow: none;
  padding: 0 0 48px;
  border-bottom: 1px solid var(--line);
  border-radius: 0;
}
[data-layout="journal"] .hero::before { display: none; }
[data-layout="journal"] .section-head {
  border-bottom: none; justify-content: center; text-align: center;
  flex-direction: column; gap: 4px; padding-bottom: 0; margin-bottom: 32px;
}
[data-layout="journal"] .section-head .more { display: none; }
[data-layout="journal"] .path-cards { grid-template-columns: 1fr; max-width: 600px; margin: 0 auto; }
[data-layout="journal"] .path-card { display: grid; grid-template-columns: 64px 1fr; gap: 18px; align-items: start; }
[data-layout="journal"] .path-card .pc-icon { margin-bottom: 0; }
[data-layout="journal"] .path-card .num { grid-column: 1; }
[data-layout="journal"] .path-card h4,
[data-layout="journal"] .path-card p,
[data-layout="journal"] .path-card .arrow { grid-column: 2; }
[data-density="airy"] .main,
[data-density="loose"] .main { padding: 56px 32px 120px; }
[data-density="airy"] .section,
[data-density="loose"] .section { margin-bottom: 84px; }
[data-density="airy"] .section-head,
[data-density="loose"] .section-head { padding-bottom: 16px; margin-bottom: 32px; }
[data-density="airy"] .hero,
[data-density="airy"] .book-head { padding: 48px; gap: 40px; }
[data-density="airy"] .review-body { padding: 56px 72px; }

[data-density="compact"] .main,
[data-density="dense"] .main { padding: 24px 32px 56px; }
[data-density="compact"] .section,
[data-density="dense"] .section { margin-bottom: 36px; }
[data-density="compact"] .section-head { padding-bottom: 8px; margin-bottom: 14px; }
[data-density="compact"] .hero,
[data-density="compact"] .book-head { padding: 24px; gap: 22px; }
[data-density="compact"] .review-body { padding: 28px 36px; }

/* motif intensity */
[data-motif="low"] .site-header::after,
[data-motif="low"] .site-footer::before,
[data-motif="subtle"] .site-header::after,
[data-motif="subtle"] .site-footer::before { opacity: 0.2; }
[data-motif="low"] .cover::after,
[data-motif="subtle"] .cover::after { opacity: 0.4; }
[data-motif="low"] .brass-divider::before,
[data-motif="low"] .brass-divider::after { opacity: 0.4; }
[data-motif="low"] .hero::before,
[data-motif="low"] .book-head::before { opacity: 0.4; }

[data-motif="high"] .site-header::after,
[data-motif="strong"] .site-header::after { opacity: 0.85; height: 4px; }
[data-motif="high"] .cover::before,
[data-motif="strong"] .cover::before {
  background: repeating-linear-gradient(45deg, transparent 0 10px, rgba(255,255,255,0.08) 10px 11px);
}
[data-motif="high"] .brand-mark,
[data-motif="strong"] .brand-mark { box-shadow: inset 0 0 0 3px var(--paper), 0 0 0 2px var(--brass-2), 0 1px 0 rgba(0,0,0,0.15); }
[data-motif="high"] .brass-divider .diamond { width: 9px; height: 9px; }

/* display font switch */
[data-display-font="shippori"] { --font-display: var(--font-mincho); }
[data-display-font="notoserif"] { --font-display: var(--font-noto-serif); }

/* dark theme tweaks */
[data-theme="foggy"] body,
[data-theme="midnight"] body,
[data-theme="foggy"],
[data-theme="midnight"] {
  background: var(--bg);
}
[data-theme="foggy"] .cover,
[data-theme="midnight"] .cover {
  box-shadow: 0 1px 0 #000, 0 18px 40px -22px rgba(0,0,0,0.7);
}

/* ============================================================
   レスポンシブ (mobile-first 補正)
   ブレイクポイント: 1024(タブレット横) / 768(タブレット縦) / 480(スマホ)
   ============================================================ */

/* 横はみ出し防止 (グローバル) */
html, body { overflow-x: hidden; }
body { -webkit-text-size-adjust: 100%; }

/* タップ操作環境ではホバーで起こる translateY を抑制 (モバイル誤発火防止) */
@media (hover: none) {
  .book-card:hover, .path-card:hover, .feature-card:hover,
  .btn:hover, .spine:hover .cover { transform: none; }
  .book-card .peek { display: none; }
}

/* ---------- ≤ 1024px (タブレット横) ---------- */
@media (max-width: 1024px) {
  .header-inner { padding: 16px 24px; }
  .nav-inner { padding: 0 20px; }
  .main { padding: 28px 24px 64px; }
}

/* ---------- ≤ 768px (タブレット縦 / 大きめスマホ) ---------- */
@media (max-width: 768px) {
  /* ヘッダー: ロゴ行と検索を縦積み */
  .header-inner {
    padding: 14px 16px;
    flex-wrap: wrap;
    gap: 12px;
  }
  .brand { gap: 10px; min-width: 0; flex: 1 1 auto; }
  .brand-mark { width: 40px; height: 40px; }
  .brand-text h1 { font-size: 16px; }
  .brand-text .tag {
    font-size: 10px; letter-spacing: 0.12em;
    /* 長すぎるタグは省略 */
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
    max-width: 60vw;
  }
  .header-search {
    margin-left: 0;
    flex: 1 1 100%;
    order: 2;
  }
  .header-search input { font-size: 16px; padding: 10px 12px 10px 36px; } /* iOS ズーム抑止 */

  /* ナビ: 横スクロール (ハンバーガー化はせず一覧性を維持) */
  .site-nav { -webkit-overflow-scrolling: touch; }
  .nav-inner {
    padding: 0 12px;
    overflow-x: auto;
    flex-wrap: nowrap;
    scrollbar-width: none;
  }
  .nav-inner::-webkit-scrollbar { display: none; }
  .site-nav a {
    padding: 12px 12px;
    font-size: 13px;
    white-space: nowrap;
    flex: 0 0 auto;
  }
  .site-nav a.is-active::after { left: 12px; right: 12px; bottom: 4px; }

  /* メイン余白を圧縮 */
  .main { padding: 20px 16px 56px; }

  /* セクション余白 */
  .section { margin-bottom: 40px; }
  .section-head {
    flex-wrap: wrap; gap: 8px 14px;
    padding-bottom: 8px; margin-bottom: 16px;
  }
  .section-head h2 { font-size: 17px; }
  .section-head .more { margin-left: auto; }

  /* ボタンはタップ領域確保 */
  .btn { padding: 10px 16px; font-size: 13px; min-height: 40px; }

  /* shelf スクロールはそのまま、padding 調整 */
  .shelf { gap: 12px; padding: 4px 2px 14px; }
  .spine { flex: 0 0 132px; }
  .spine .cover { width: 132px; height: 192px; padding: 12px 10px; }

  /* book-card */
  .book-card { padding: 14px; gap: 12px; grid-template-columns: 76px 1fr; }
  .book-card .cover { width: 76px; height: 108px; padding: 8px 7px; }
  .book-card .meta h3 { font-size: 14.5px; }
  .book-card .peek { display: none; }

  /* footer */
  .site-footer { padding: 24px 16px 28px; }
  .header-search { font-size: 13px; }
}

/* ---------- ≤ 480px (スマホ) ---------- */
@media (max-width: 480px) {
  .header-inner { padding: 12px 14px; }
  .brand-mark { width: 36px; height: 36px; }
  .brand-mark img { width: 26px; height: 26px; }
  .brand-text h1 { font-size: 15px; letter-spacing: 0.02em; }
  .brand-text .tag { display: none; }

  .nav-inner { padding: 0 8px; }
  .site-nav a { padding: 11px 10px; font-size: 12.5px; letter-spacing: 0.02em; }

  .main { padding: 16px 14px 48px; }
  .section { margin-bottom: 32px; }

  /* shelf を少し小さく */
  .spine { flex: 0 0 116px; }
  .spine .cover { width: 116px; height: 168px; padding: 10px 9px; }
  .spine .cover .c-title { font-size: 11.5px; }
  .spine .meta .ttl { font-size: 12px; }

  .btn { font-size: 12.5px; padding: 9px 14px; }

  /* density のうるさい余白を中和 (airy/loose 適用時にスマホで行き過ぎないよう) */
  [data-density="airy"] .main,
  [data-density="loose"] .main { padding: 24px 14px 56px; }
  [data-density="airy"] .section,
  [data-density="loose"] .section { margin-bottom: 44px; }
}