/* ── 目录侧边栏 Drawer ──────────────────────────────────── */
.bk-toc-drawer {
  position: fixed;
  top: 0;
  left: 0;
  width: 320px;
  max-width: 85vw;
  height: 100vh;
  background: var(--surface, #fff);
  z-index: 1000;
  transform: translateX(-100%);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  border-right: 1px solid var(--border, #E5E2DD);
  display: flex;
  flex-direction: column;
}
.bk-toc-drawer.open {
  transform: translateX(0);
}
.bk-toc-overlay {
  position: fixed;
  inset: 0;
  background: var(--overlay-strong, rgba(44, 24, 16, 0.38));  /* C5: 改用暖色遮罩令牌，与设计系统一致 */
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}
.bk-toc-overlay.open {
  opacity: 1;
  pointer-events: auto;
  touch-action: none;
}
.bk-toc-drawer-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 16px 14px 12px;
  border-bottom: 1px solid var(--border, #E5E2DD);
  flex-shrink: 0;
  gap: 8px;
}
.bk-toc-drawer-titles { flex: 1; min-width: 0; }
.bk-toc-drawer-book-title {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--heading, #111);
  line-height: 1.4;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}
.bk-toc-drawer-author {
  font-size: var(--text-sm);
  color: var(--text-muted, #888);
  margin-top: 2px;
}
.bk-toc-drawer-close {
  min-width: 44px;
  min-height: 44px;
  border-radius: 50%;
  border: none;
  background: var(--surface-alt, #EDEAE4);
  color: var(--text-muted, #888);
  cursor: pointer;
  font-size: var(--text-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  -webkit-tap-highlight-color: transparent;
  transition: background 0.15s;
}
.bk-toc-drawer-close:active { background: var(--nav-hover, #ECEAE5); }
.bk-toc-search {
  flex-shrink: 0;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border, #E5E2DD);
}
.bk-toc-search-input {
  width: 100%;
  box-sizing: border-box;
  padding: 8px 12px;
  border: 1px solid var(--border, #E5E2DD);
  border-radius: 8px;
  font-size: var(--text-base);
  outline: none;
  background: var(--surface-alt, #EDEAE4);
  color: var(--text, #1A1918);
  transition: border-color 0.15s;
}
.bk-toc-search-input:focus {
  border-color: var(--brand, #3D8A5A);
}
.bk-toc-search-input::placeholder {
  color: var(--text-muted, #aaa);
}
.bk-toc-chapter-item.bk-toc-hidden { display: none; }
.bk-toc-no-results {
  padding: 24px 16px;
  text-align: center;
  color: var(--text-muted, #888);
  font-size: var(--text-base);
}
.bk-toc-drawer-body {
  flex: 1;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
}
.bk-toc-chapter-list {
  display: flex;
  flex-direction: column;
}
.bk-toc-chapter-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 16px;
  text-decoration: none;
  color: var(--text, #1A1918);
  font-size: var(--text-base);
  border-bottom: 1px solid var(--border, #E5E2DD);
  transition: background 0.15s;
  -webkit-tap-highlight-color: transparent;
  cursor: pointer;
}
.bk-toc-chapter-item:active { background: var(--nav-hover, #ECEAE5); }
.bk-toc-chapter-item.bk-toc-current {
  background: var(--nav-hover, #ECEAE5);
  color: var(--brand, #3D8A5A);
  font-weight: 500;
}
.bk-toc-chapter-num {
  font-size: var(--text-xs);
  font-family: var(--num-font-family);
  font-variant-numeric: tabular-nums;
  color: var(--text-muted, #888);
  min-width: 28px;
  text-align: right;
  flex-shrink: 0;
}
.bk-toc-chapter-title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 1.1em;
  line-height: 1.4;
}
.bk-toc-chapter-badge {
  font-size: var(--text-xs);
  background: var(--brand, #3D8A5A);
  color: #fff;
  border-radius: 10px;
  padding: 1px 7px;
  flex-shrink: 0;
}

/* ── 书籍下载状态徽章（书城卡 .zl-book-card.is-city-book 内的 .cache-status） ────
 * 设计原则：
 *  - 常态空徽章不显示（:empty 选择器），避免冗余 ☁/✓ 角标干扰封面海报视觉
 *  - 下载中：橙色脉冲 + 禁用 .book-link 再次点击（pointer-events:none）
 *  - 失败：红色徽章不脉冲，状态保留供用户查看/重试
 * 文字内容（如「⏳ 下载中 50%」「✓ 已下载」「✗ 下载失败」）由 _handleBookClick 写入，
 * CSS 仅负责定位、配色与动画。
 * ----------------------------------------------------------------------------- */
.zl-book-card.is-city-book .cache-status {
  position: absolute;
  top: 8px;
  right: 8px;
  margin: 0;
  padding: 3px 9px;
  border-radius: 11px;
  background: rgba(26, 25, 24, 0.82);
  color: #fff;
  font-size: var(--text-xs, 11px);
  font-weight: 500;
  letter-spacing: 0.02em;
  opacity: 0;
  transform: translateY(-3px);
  transition: opacity .2s var(--ease-out, ease), transform .2s var(--ease-out, ease);
  pointer-events: none;
  z-index: 3;
  max-width: calc(100% - 16px);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 内容非空时显示（由 JS 设置 textContent → :empty 自动判断） */
.zl-book-card.is-city-book .cache-status:not(:empty) {
  opacity: 1;
  transform: translateY(0);
}

/* 兼容旧通用规则：css-base.css 中 .zl-book-card .cache-status 用了 margin-left/opacity 等
 * flex-item 样式，城市卡用绝对定位覆盖之。已下载未失败的常态下 _refreshAfterDownload 会清空
 * textContent，:empty 触发 opacity:0 -> 回到不可见。 */

@keyframes bk-pulse {
  0%, 100% { opacity: 0.78; transform: translateY(0) scale(0.98); }
  50%      { opacity: 1;    transform: translateY(0) scale(1.04); }
}

/* 下载中：橙色文字 + 脉冲动画 */
.zl-book-card.is-city-book[data-downloading="true"] .cache-status {
  color: var(--warning-text, #B5793A);
  background: rgba(26, 25, 24, 0.85);
  animation: bk-pulse 1.2s ease-in-out infinite;
}

/* 下载中：禁用 .book-link 再次点击（防抖）；视觉上轻降饱和度提示忙碌 */
.zl-book-card.is-city-book[data-downloading="true"] .book-link {
  pointer-events: none;
  cursor: default;
}
.zl-book-card.is-city-book[data-downloading="true"] .bk-cover {
  filter: saturate(0.85) brightness(0.96);
  transition: filter .25s ease;
}

/* 下载失败：红色徽章不脉冲，状态保留 */
.zl-book-card.is-city-book[data-download-failed="true"] .cache-status {
  animation: none;
  color: #fff;
  background: rgba(200, 85, 61, 0.88);
}