:root {
  --primary: #007bff;
  --bg: #f5f6f8;
  --card: #ffffff;
  --text: #222;
  --muted: #666;
  --shadow: 0 4px 16px rgba(0,0,0,0.08);
  --border: #e6e6e6;
  
  /* 为顶栏添加一个特定的背景色 */
  --topbar-bg: #ffffff;
}

body.dark {
  --bg: #0f1216;
  --card: #12171d;
  --text: #e6edf3;
  --muted: #9aa7b2;
  --border: #1f2630;
  --shadow: 0 10px 30px rgba(0,0,0,0.45);
  --topbar-bg: #12171d;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  padding: 12px;
}

.container { 
  max-width: 1160px; 
  margin: 0 auto; 
}

/* MODIFIED: .topbar 样式修改为绝对定位，作为下拉菜单 */
.topbar {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  right: 0;
  width: 100%;
  z-index: 20;
  display: flex; 
  align-items: center; 
  justify-content: space-between; 
  gap: 8px;
  margin-bottom: 0; /* 不再需要外边距 */
  padding: 8px 10px; 
  border: 1px solid var(--border); 
  border-radius: 12px;
  background: var(--card);
  box-shadow: var(--shadow);
  transition: transform .25s ease, opacity .25s ease;
}

.left, .right { 
  display: flex; 
  align-items: center; 
  gap: 10px; 
  flex-wrap: wrap; 
}

/* 统一按钮尺寸与样式 */
.icon-btn {
  width: 36px; 
  height: 36px; 
  display: inline-flex; 
  align-items: center; 
  justify-content: center;
  border-radius: 10px; 
  border: 1px solid var(--border); 
  background: #fff; 
  color: var(--text);
  cursor: pointer; 
  box-shadow: var(--shadow);
}

.back { 
  text-decoration: none; 
}

.meta { 
  color: var(--muted); 
  font-size: 0.95rem; 
}

.title-ellipsis { 
  max-width: 52vw; 
  overflow: hidden; 
  text-overflow: ellipsis; 
  white-space: nowrap; 
}

.btn, .select {
  height: 36px; 
  padding: 0 12px; 
  border: 1px solid var(--border); 
  border-radius: 10px; 
  background: #fff; 
  cursor: pointer; 
  color: var(--text);
  display: inline-flex; 
  align-items: center; 
  gap: 6px; 
  font-size: 14px;
}

.btn:hover, .icon-btn:hover { 
  background: var(--bg);
  border-color: var(--primary);
}

/* MODIFIED: 折叠规则改为 transform，实现平滑下拉动画 */
.collapsed .topbar {
  transform: translateY(-10px);
  opacity: 0;
  pointer-events: none;
}

/* 顶栏切换按钮 */
#topbar-toggle { 
  display: inline-flex; 
}

.info-toggle {
  width: 30px; 
  height: 30px; 
  display: inline-flex; 
  align-items: center; 
  justify-content: center;
  border-radius: 8px; 
  border: 1px solid var(--border);
  background: #fff; 
  color: var(--text); 
  box-shadow: var(--shadow);
  cursor: pointer; 
  user-select: none;
}

.sep { 
  width: 1px; 
  height: 24px; 
  background: var(--border); 
}

.cover-box { 
  width: 18px; 
  height: 18px; 
  border-radius: 4px; 
  background: #ddd; 
  background-size: cover; 
  background-position: center; 
  display: inline-block; 
}

.card { 
  background: var(--card); 
  border-radius: 10px; 
  box-shadow: var(--shadow); 
}

.controls { 
  display: flex; 
  align-items: center; 
  gap: 10px; 
  padding: 10px 12px; 
  border: 1px solid var(--border); 
  border-radius: 10px; 
  background: #fff; 
}

.progress { 
  display: flex; 
  align-items: center; 
  gap: 10px; 
  margin: 6px 0; 
}

.range { 
  flex: 1; 
}

input[type=range] { 
  width: 100%; 
}

.percent { 
  display: block; 
  min-width: 80px; 
  text-align: right; 
  font-size: 14px; 
  color: var(--muted); 
}

/* 使用与进度条一致的视觉风格为返回按钮着色 */
.back.icon-btn {
  background: linear-gradient(135deg, rgba(91,140,255,0.15), rgba(122,92,255,0.20));
  color: var(--primary);
  border-color: rgba(91,140,255,0.35);
}

.back.icon-btn:hover { 
  background: rgba(91,140,255,0.18); 
}

/* 选区操作条 */
#selbar { 
  display: none; 
  margin: 8px 0; 
}

.hl-chip { 
  padding: 4px 10px; 
  border-radius: 999px; 
  border: 1px solid var(--border); 
  cursor: pointer; 
  background: #fff; 
}

.hl-yellow { 
  background: rgba(255, 230, 0, 0.35); 
}

.hl-green { 
  background: rgba(46, 204, 113, 0.30); 
}

.hl-pink { 
  background: rgba(255, 99, 132, 0.30); 
}

#reader-card { 
  padding: 0; 
}

#viewer-container { 
  position: relative; 
  width: 100%; 
  height: 78vh; 
  border-radius: 10px; 
  overflow: hidden; 
}

/* 骨架层 */
#reader-skeleton { 
  position: absolute; 
  inset: 0; 
  display: none; 
  background: linear-gradient(90deg, rgba(240,240,240,0.9), rgba(250,250,250,0.9), rgba(240,240,240,0.9)); 
  background-size: 200% 100%; 
  animation: shimmer 1.2s linear infinite; 
}

@keyframes shimmer { 
  0% { background-position: 200% 0; } 
  100% { background-position: -200% 0; } 
}

#viewer { 
  width: 100%; 
  height: 100%; 
}

#nav { 
  position: absolute; 
  inset: 0; 
  display: flex; 
  justify-content: space-between; 
  pointer-events: none; 
}

#prev, #next {
  width: 3%; 
  height: 100%; 
  display: flex; 
  align-items: center; 
  justify-content: center;
  font-size: 2rem; 
  color: rgba(0,0,0,0.15); 
  cursor: pointer; 
  pointer-events: auto; 
  user-select: none;
  transition: background-color .2s, color .2s;
}

#prev:hover, #next:hover { 
  background: rgba(0,0,0,0.05); 
  color: rgba(0,0,0,0.4); 
}

/* 点击后立即恢复默认状态，避免影响阅读 */
#prev:active, #next:active {
  background: rgba(0,0,0,0.15);
  color: rgba(0,0,0,0.15);
}

/* 移动端优化：完全透明的遮罩，提升阅读体验 */
@media (max-width: 768px) {
  #nav #prev, #nav #next {
    width: 25% !important; /* 移动端保持较宽的触摸区域 */
    color: transparent !important; /* 完全透明的默认状态 */
  }
  
  #nav #prev:hover, #nav #next:hover {
    background: rgba(0,0,0,0.01) !important; /* 极轻微提示 */
    color: rgba(0,0,0,0.1) !important;
  }
  
  #nav #prev:active, #nav #next:active {
    background: transparent !important; /* 完全透明的点击状态 */
    color: transparent !important;
  }
}

/* 侧栏（目录 / 书签） */
.drawer {
  position: fixed; 
  top: 0; 
  bottom: 0; 
  right: -340px; 
  width: 320px; 
  background: #fff; 
  box-shadow: -2px 0 16px rgba(0,0,0,0.1);
  transition: right .25s ease; 
  padding: 12px; 
  z-index: 50; 
  overflow: auto; 
  border-left: 1px solid var(--border);
}

.drawer.open { 
  right: 0; 
}

.drawer h3 { 
  margin: 6px 0 10px; 
  font-size: 1.05rem; 
}

.toc-list, .bm-list { 
  list-style: none; 
  padding: 0; 
  margin: 0; 
}

.toc-item, .bm-item { 
  padding: 8px 6px; 
  border-bottom: 1px solid #f0f0f0; 
  cursor: pointer; 
}

.toc-item:hover, .bm-item:hover { 
  background: #fafafa; 
}

.bm-actions { 
  display: flex; 
  gap: 8px; 
}

.muted { 
  color: var(--muted); 
  font-size: 12px; 
}

.cover-large { 
  width: 100%; 
  max-height: 50vh; 
  object-fit: contain; 
  border-radius: 8px; 
  background: #f2f2f2; 
}

.meta-table { 
  margin: 8px 0 0; 
  font-size: 14px; 
}

.meta-table dt { 
  color: var(--muted); 
}

.meta-table dd { 
  margin: 0 0 8px; 
}

.error { 
  background: #fff3f3; 
  color: #a30000; 
  padding: 12px; 
  border-radius: 8px; 
  margin-top: 10px; 
  display: none; 
}

/* 帮助弹窗 */
.modal {
  position: fixed; 
  inset: 0; 
  display: none; 
  align-items: center; 
  justify-content: center; 
  z-index: 60;
  background: rgba(0,0,0,0.35);
}

.modal.open { 
  display: flex; 
}

.modal-card {
  width: min(680px, 92vw); 
  max-height: 80vh; 
  overflow: auto;
  background: var(--card); 
  color: var(--text); 
  border: 1px solid var(--border);
  border-radius: 12px; 
  box-shadow: var(--shadow); 
  padding: 14px 16px;
}

.modal-card h3 { 
  margin: 6px 0 10px; 
}

.kbd { 
  display: inline-block; 
  padding: 2px 6px; 
  border-radius: 6px; 
  border: 1px solid var(--border); 
  background: #fff; 
  margin: 0 4px; 
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; 
}

/* 遮罩 */
#overlay { 
  position: fixed; 
  inset: 0; 
  background: rgba(0,0,0,0.35); 
  display: none; 
  z-index: 45; 
}

/* epub.js 标注颜色（通过自定义类名） */
.epubjs-hl.hl-yellow { 
  fill: rgba(255, 230, 0, 0.45) !important; 
  mix-blend-mode: multiply; 
}

.epubjs-hl.hl-green { 
  fill: rgba(46, 204, 113, 0.45) !important; 
  mix-blend-mode: multiply; 
}

.epubjs-hl.hl-pink { 
  fill: rgba(255, 99, 132, 0.45) !important; 
  mix-blend-mode: multiply; 
}

/* 搜索结果 */
#search-results { 
  list-style: none; 
  padding: 0; 
  margin: 6px 0 0; 
}

#search-results li { 
  padding: 8px 6px; 
  border-bottom: 1px solid var(--border); 
  cursor: pointer; 
}

#search-results li:hover { 
  background: #fafafa; 
}

/* 信息卡片化布局模式 */
#info-card {
  position: relative; 
  display: block; 
  margin: 8px 0 6px; 
  padding: 10px 12px; 
  border: 1px solid var(--border); 
  border-radius: 12px; 
  background: var(--card); 
  box-shadow: var(--shadow);
}

#info-card .line1 { 
  display: flex; 
  align-items: center; 
  gap: 8px; 
}

#info-card .name { 
  font-weight: 600;
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
}

#info-card .author { 
  color: var(--muted); 
  font-size: 12px; 
}

/* 下载按钮样式 */
#info-card .download-btn {
  margin-left: auto;
  width: 30px;
  height: 30px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--primary);
  box-shadow: var(--shadow);
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
}

#info-card .download-btn:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

#info-card .download-btn:active {
  transform: scale(0.95);
}

#book-meta { 
  display: none; 
}

.topbar .back { 
  display: none; 
}

#info-card .info-back {
  width: 30px; 
  height: 30px;
  display: inline-flex; 
  align-items: center; 
  justify-content: center;
  border-radius: 8px; 
  border: 1px solid var(--border);
  background: #fff; 
  color: var(--text);
  box-shadow: var(--shadow); 
  cursor: pointer; 
  text-decoration: none;
  font-size: inherit;
  font-family: inherit;
}

#info-card .info-back:hover,
.back.icon-btn:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

#info-card .info-back:active,
.back.icon-btn:active {
  transform: scale(0.95);
}

.info-toc {
  width: 30px; 
  height: 30px; 
  display: inline-flex; 
  align-items: center; 
  justify-content: center;
  border-radius: 8px; 
  border: 1px solid var(--border);
  background: #fff; 
  color: var(--text);
  box-shadow: var(--shadow); 
  cursor: pointer; 
  transition: all 0.2s ease;
}

.info-toc:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.info-toc:hover span span {
  background: #fff !important;
}

.info-toc:active {
  transform: scale(0.95);
}

@media (max-width: 768px) {
  body { 
    padding: 8px; 
  }
  
  #viewer-container { 
    height: 75vh; 
  }
  
  .drawer { 
    width: 88%; 
    right: -90%; 
  }
  
  .drawer.open { 
    right: 0; 
  }
}