:root {
  --bg-primary: #FAF6ED;
  --bg-secondary: #F2ECDD;
  --placeholder-bg: #EAE4D5;
  --border-medium: #C9BFA7;
  --border-subtle: #D8CDB2;
  --text-heading: #1F1A14;
  --text-primary: #2C2620;
  --text-sub: #6B5F4C;
  --text-muted: #71644F; /* contrast 5.35:1 on #FAF6ED (WCAG AA pass) */
  --text-light: #7C6F5A; /* contrast 4.55:1 on #FAF6ED (WCAG AA pass) */
  --accent: #7A5C3A;
  --accent-new: #C04818;
  --accent-sale: #B5341C;
  --font-sans: 'Hiragino Sans', 'Yu Gothic', 'Noto Sans JP', sans-serif;
  --font-serif: 'Hiragino Mincho ProN', 'Yu Mincho', 'Noto Serif JP', serif;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 0 18px;
}

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

img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* サイトヘッダー */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 18px 0 12px;
}

.logo {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 500;
  color: var(--text-heading);
  letter-spacing: 0.04em;
}

.last-update {
  font-size: 11px;
  color: var(--text-muted);
}

/* プライマリタブ */
.primary-tabs {
  display: flex;
  border-bottom: 1px solid var(--border-medium);
  margin-bottom: 10px;
}

.primary-tab {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 0;
  font-size: 13px;
  color: var(--text-muted);
  transition: color 0.1s;
}

.primary-tab.active {
  color: var(--text-heading);
  font-weight: 500;
  border-bottom: 2px solid var(--accent);
  margin-bottom: -1px;
}

/* 件数表示 */
.count-bar {
  padding: 8px 0;
  font-size: 11px;
  color: var(--text-sub);
}

.count-separator {
  margin: 0 4px;
}

.new-dot {
  color: var(--accent-new);
}

/* 本別タブの件数表示 */
.count-bar-books {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.count-sort {
  color: var(--text-sub);
}

/* ジャンルタブ */
.genre-tabs {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  white-space: nowrap;
  padding: 0 18px 12px;
  margin: 0 -18px;
  scrollbar-width: none;
}
.genre-tabs::-webkit-scrollbar {
  display: none;
}

.genre-tab {
  flex-shrink: 0;
  min-height: 44px;
  padding: 0 14px;
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--border-medium);
  border-radius: 4px;
  font-size: 13px;
  color: var(--text-primary);
  background: var(--bg-primary);
}

.genre-tab.active {
  background: var(--accent);
  color: var(--bg-primary);
  border-color: var(--accent);
  font-weight: 500;
}

/* セールカード */
.sale-list {
  display: block;
}

.sale-card {
  display: flex;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border-subtle);
  transition: transform 0.1s;
}
.sale-card:last-child {
  border-bottom: none;
}
.sale-card:active {
  transform: scale(0.98);
}

.sale-card-thumbs {
  display: flex;
  gap: 3px;
  flex-shrink: 0;
}

.sale-card-thumb {
  width: 42px;
  height: 62px;
  background: var(--placeholder-bg);
  box-shadow: 1px 2px 3px rgba(44, 38, 32, 0.15);
}

.sale-card-body {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 4px;
}

.sale-card-badges {
  display: flex;
  gap: 4px;
}

.badge {
  display: inline-block;
  padding: 1px 5px;
  border-radius: 2px;
  font-size: 9px;
  font-weight: 500;
  line-height: 1.4;
}

.badge-new {
  background: var(--accent-new);
  color: #FFFFFF;
}

.badge-genre {
  background: var(--bg-primary);
  border: 1px solid var(--border-medium);
  color: var(--text-sub);
  font-weight: 400;
  font-size: 10px;
}

.sale-card-title {
  margin: 0;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.35;
  color: var(--text-heading);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.sale-card-meta {
  font-size: 11px;
  color: var(--text-sub);
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0;
}

.meta-separator {
  margin: 0 4px;
  color: var(--text-muted);
}

.meta-count {
  color: var(--text-heading);
  font-weight: 500;
}

.meta-discount {
  color: var(--accent-sale);
  font-weight: 500;
}

.meta-remaining {
  color: var(--text-sub);
  font-weight: 500;
}

.meta-remaining.urgent {
  color: var(--accent-sale);
}

/* 空メッセージ */
.empty-message {
  padding: 24px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
}

/* 本カード (flat コンテキスト) */
.book-list {
  display: block;
}

.book-card-flat {
  display: flex;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border-subtle);
  transition: transform 0.1s;
}
.book-card-flat:last-child {
  border-bottom: none;
}
.book-card-flat:active {
  transform: scale(0.98);
}

.book-card-thumb-flat {
  width: 52px;
  height: 76px;
  flex-shrink: 0;
  background: var(--placeholder-bg);
  box-shadow: 1px 2px 3px rgba(44, 38, 32, 0.15);
}

.book-card-body {
  flex: 1;
  min-width: 0;
}

.book-card-title {
  margin: 0 0 2px;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.35;
  color: var(--text-heading);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-card-meta {
  font-size: 10px;
  color: var(--text-muted);
  margin-bottom: 4px;
  line-height: 1.4;
}

.book-card-meta .sale-label {
  color: var(--text-muted);
}

.book-card-price-row {
  display: flex;
  align-items: baseline;
  gap: 6px;
  flex-wrap: wrap;
}

.price-original {
  font-size: 11px;
  color: var(--text-light);
  text-decoration: line-through;
}

.price-sale {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-heading);
}

.price-discount-real {
  font-size: 11px;
  font-weight: 500;
  color: var(--accent-sale);
}

/* 戻るヘッダー */
.back-header {
  padding: 10px 0;
  border-bottom: 1px solid var(--border-medium);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 44px;
  color: var(--text-sub);
}

.back-arrow {
  font-size: 18px;
  line-height: 1;
}

.back-text {
  font-size: 13px;
}

/* セール詳細ヘッダー */
.sale-detail-header {
  padding: 16px 0 14px;
}

.sale-detail-title {
  margin: 6px 0 0;
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 500;
  line-height: 1.4;
  color: var(--text-heading);
}

.sale-detail-meta {
  margin-top: 8px;
  font-size: 12px;
  color: var(--text-sub);
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0;
}

/* ソート・絞り込みバー */
.sort-filter-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  padding: 10px 18px;
  margin: 0 -18px;
  font-size: 13px;
}

.sort-control {
  color: var(--text-primary);
}

.sort-select {
  border: none;
  background: transparent;
  font-family: inherit;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  padding: 0;
  min-height: 44px;
  cursor: pointer;
}

.filter-button {
  border: none;
  background: transparent;
  color: var(--text-sub);
  font-size: 13px;
  font-family: inherit;
  padding: 0;
  min-height: 44px;
  cursor: pointer;
}
.filter-button:disabled {
  cursor: not-allowed;
  opacity: 0.7;
}

/* 本カード (detail コンテキスト) */
.book-card-detail {
  display: flex;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border-subtle);
  transition: transform 0.1s;
}
.book-card-detail:last-child {
  border-bottom: none;
}
.book-card-detail:active {
  transform: scale(0.98);
}

.book-card-thumb-detail {
  width: 66px;
  height: 96px;
  flex-shrink: 0;
  background: var(--placeholder-bg);
  box-shadow: 1px 2px 3px rgba(44, 38, 32, 0.15);
}

.book-card-price-row-primary {
  display: flex;
  align-items: baseline;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 6px;
}

.price-sale-detail {
  font-size: 17px;
  font-weight: 500;
  color: var(--text-heading);
}

.price-discount-nominal {
  font-size: 12px;
  color: var(--text-sub);
}

.book-card-price-row-real {
  display: flex;
  align-items: baseline;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 3px;
}

.price-point-back {
  font-size: 10px;
  color: var(--text-muted);
}

.price-real {
  font-size: 13px;
  font-weight: 500;
  color: var(--accent-sale);
}

.price-discount-real-inline {
  font-size: 11px;
  font-weight: 500;
  color: var(--accent-sale);
}

/* さらに表示ボタン */
.load-more-wrapper {
  padding: 14px 18px;
  text-align: center;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  margin: 0 -18px;
}

.load-more-button {
  padding: 10px 24px;
  background: var(--bg-primary);
  border: 1px solid var(--border-medium);
  border-radius: 4px;
  font-size: 13px;
  color: var(--text-primary);
  cursor: pointer;
  font-family: inherit;
  transition: transform 0.1s;
}
.load-more-button:active {
  transform: scale(0.98);
}

/* フッター */
.site-footer {
  max-width: 600px;
  margin: 20px auto 0;
  padding: 14px 18px 20px;
  border-top: 1px solid var(--border-medium);
}

.footer-notice {
  margin: 4px 0;
  font-size: 10px;
  color: var(--text-light);
  line-height: 1.6;
}

/* キーボードフォーカスの可視化 (アクセシビリティ) */
.primary-tab:focus-visible,
.genre-tab:focus-visible,
.sale-card:focus-visible,
.book-card-flat:focus-visible,
.book-card-detail:focus-visible,
.back-link:focus-visible,
.load-more-button:focus-visible,
.filter-button:focus-visible,
.sort-select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* PC 表示時の余白 */
@media (min-width: 768px) {
  body {
    background: #E8E4DB;
  }
  .container {
    background: var(--bg-primary);
    min-height: 100vh;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.04);
  }
  .site-footer {
    background: var(--bg-primary);
  }
}