/* ========================================================
   豆瓣阅读风格 沉浸式阅读器 (Reader)
   高仿双层背景卡片质感、纯净视觉、纸张悬浮实体质感
   上下到顶 (Full Viewport Height) · 1:1 信息密度与楷体排版
   ======================================================== */

:root {
  --font-kai: "STKaiti", "KaiTi", "Kaiti SC", "楷体", "BiauKai", "FangSong", "Noto Serif SC", serif;
  --font-song: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", "STSong", serif;
  --font-hei: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-serif: var(--font-kai);

  --page-stage-gap: 80px;
  --stage-content-h: 800px;
  --paper-w: 780px;
  --paper-padding-x: 52px;
  --stage-inner-w: calc(var(--paper-w) - var(--paper-padding-x) * 2); /* 676px */
}

/* 4 套双层背景主题定义 (外层桌布背景 vs 内层纸张卡片) */
body.theme-paper {
  --bg-desktop: #ece8df;
  --bg-paper: #fcfbfa;
  --text-main: #2b2b2b;
  --text-faint: #969186;
  --reader-border: #e0dcd2;
  --reader-muted: #75716b;
  --reader-card: #fcfbfa;
  --brand-green: #387642;
  --paper-shadow: 0 0 24px rgba(0, 0, 0, 0.05), 0 0 2px rgba(0, 0, 0, 0.04);
}

body.theme-eye {
  --bg-desktop: #dce5dc;
  --bg-paper: #eef5ee;
  --text-main: #203322;
  --text-faint: #687e6b;
  --reader-border: #ccd8cc;
  --reader-muted: #5e7361;
  --reader-card: #eef5ee;
  --brand-green: #2e6637;
  --paper-shadow: 0 0 24px rgba(32, 51, 34, 0.05), 0 0 2px rgba(32, 51, 34, 0.04);
}

body.theme-parchment {
  --bg-desktop: #e7ddcb;
  --bg-paper: #faf4ea;
  --text-main: #342a1e;
  --text-faint: #8a7c68;
  --reader-border: #dcd0bc;
  --reader-muted: #7d6e5c;
  --reader-card: #faf4ea;
  --brand-green: #5c4728;
  --paper-shadow: 0 0 24px rgba(52, 42, 30, 0.06), 0 0 2px rgba(52, 42, 30, 0.04);
}

body.theme-night {
  --bg-desktop: #121316;
  --bg-paper: #1c1d22;
  --text-main: #a6a8b0;
  --text-faint: #5a5c66;
  --reader-border: #282a30;
  --reader-muted: #6e717a;
  --reader-card: #1c1d22;
  --brand-green: #4caf50;
  --paper-shadow: 0 0 28px rgba(0, 0, 0, 0.6);
}

/* 版宽变量切换 (预留 8px 安全呼吸裕量，彻底杜绝楷体书法外延笔画、标点与两端对齐切字) */
body.width-normal {
  --paper-w: 780px;
  --paper-padding-x: 50px;
  --stage-inner-w: calc(780px - 100px - 2px); /* 678px */
  --stage-col-w: calc(var(--stage-inner-w) - 8px); /* 670px */
}

body.width-wide {
  --paper-w: 920px;
  --paper-padding-x: 50px;
  --stage-inner-w: calc(920px - 100px - 2px); /* 818px */
  --stage-col-w: calc(var(--stage-inner-w) - 8px); /* 810px */
}

/* 基础通用属性 */
.reader-body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  transition: background-color 0.25s ease, color 0.25s ease;
  user-select: text;
  background-color: var(--bg-desktop) !important;
  color: var(--text-main) !important;
  box-sizing: border-box;
}

/* 左上角极简轻透返回胶囊 */
.reader-top-left-back {
  position: fixed;
  left: 28px;
  top: 20px;
  z-index: 95;
}

.btn-reader-back-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(0, 0, 0, 0.05);
  border-radius: 16px;
  font-size: 13px;
  color: var(--reader-muted);
  text-decoration: none;
  transition: all 0.2s ease;
  backdrop-filter: blur(4px);
}

body.theme-night .btn-reader-back-pill {
  background: rgba(255, 255, 255, 0.08);
  color: #a8aab0;
}

.btn-reader-back-pill:hover {
  background: rgba(0, 0, 0, 0.1);
  color: var(--text-main);
  transform: translateX(-2px);
}

/* ========================================================
   阅读核心：双层卡片与视口舞台 (上下到顶 100vh)
   ======================================================== */

/* 1. 分页阅读模式 (mode-paged, 默认) */
body.mode-paged {
  height: 100vh !important;
  overflow: hidden !important;
  position: fixed !important;
  width: 100% !important;
}

body.mode-paged .reader-viewport {
  position: relative;
  width: 100vw;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: stretch; /* 上下到顶 */
  overflow: hidden;
  box-sizing: border-box;
}

/* 纸张包裹外壳 (用于与右侧工具、翻页条相对定位) */
.reader-stage-wrapper {
  position: relative;
  display: flex;
  justify-content: center;
  height: 100vh; /* 满视口高度 */
}

/* 悬浮实体图书纸张卡片 (截图同款：上下贯穿到顶，左右自然余白) */
.reader-paper-sheet {
  background: var(--bg-paper);
  box-shadow: var(--paper-shadow);
  border-radius: 0; /* 上下到顶贴合边缘，无圆角 */
  box-sizing: border-box;
  padding: 28px var(--paper-padding-x, 52px) 16px;
  position: relative;
  display: flex;
  flex-direction: column;
  transition: background-color 0.25s ease, box-shadow 0.25s ease; /* 严禁对 width 添加过渡，确保多列重排瞬间完成不撕裂 */
  height: 100vh !important; /* 强制上下到顶 100vh */
  border-left: 1px solid rgba(0, 0, 0, 0.03);
  border-right: 1px solid rgba(0, 0, 0, 0.03);
  border-top: none;
  border-bottom: none;
}

body.mode-paged .reader-paper-sheet.width-normal {
  width: var(--paper-w, 780px);
  max-width: calc(100vw - 120px);
}

body.mode-paged .reader-paper-sheet.width-wide {
  width: var(--paper-w, 920px);
  max-width: calc(100vw - 110px);
}

/* 纸张书眉 Running Head (天头：左对齐淡雅标识) */
.reader-running-head {
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  margin-bottom: 6px;
  user-select: none;
  flex-shrink: 0;
  padding: 0 2px;
}

#runningHeadChapter {
  font-family: var(--font-serif);
  font-size: 13px;
  color: var(--text-faint);
  letter-spacing: 0.06em;
  opacity: 0.75;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 90%;
}

/* 纸张地脚 Running Foot (截图同款：左下角纯页码，淡雅干净) */
.reader-page-foot {
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 6px;
  user-select: none;
  flex-shrink: 0;
  padding: 0 2px;
}

#runningPageNumber {
  font-family: var(--font-serif);
  font-size: 13px;
  color: var(--text-faint);
  letter-spacing: 0.04em;
  opacity: 0.75;
}

/* 纸张最底边极细阅读进度指示条 (截图同款) */
.paper-bottom-progress {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: rgba(0, 0, 0, 0.04);
  overflow: hidden;
}

body.theme-night .paper-bottom-progress {
  background: rgba(255, 255, 255, 0.06);
}

.paper-progress-fill {
  height: 100%;
  width: 0%;
  background: rgba(0, 0, 0, 0.28);
  transition: width 0.22s ease;
}

body.theme-night .paper-progress-fill {
  background: rgba(255, 255, 255, 0.38);
}

/* 纸张内部的舞台：根据基线行高自适应充满视口 */
body.mode-paged .reader-page-stage {
  flex: 1;
  width: 100% !important;
  max-width: 100% !important;
  height: var(--stage-content-h, calc(100vh - 102px)) !important;
  overflow: hidden !important;
  position: relative !important;
  box-sizing: border-box !important;
}

body.mode-paged .reader-container {
  height: 100% !important;
  width: var(--stage-col-w, 670px);
  max-width: 100%;
  margin: 0 !important;
  padding: 0 !important;
  box-sizing: border-box !important;
  column-width: var(--stage-col-w, 670px);
  column-gap: var(--page-stage-gap, 80px) !important;
  column-fill: auto !important;
  transition: transform 0.28s cubic-bezier(0.16, 1, 0.3, 1);
  user-select: text;
}

/* 紧随纸张右上角的极简工具栏 (截图同款) */
.paper-aside-tools {
  position: absolute;
  left: calc(100% + 14px);
  top: 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 95;
}

.tool-icon-btn {
  width: 34px;
  height: 34px;
  border-radius: 4px;
  background: rgba(0, 0, 0, 0.05);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--reader-muted);
  transition: all 0.2s ease;
  outline: none;
}

body.theme-night .tool-icon-btn {
  background: rgba(255, 255, 255, 0.08);
  color: #a8aab0;
}

.tool-icon-btn:hover {
  background: rgba(0, 0, 0, 0.12);
  color: var(--text-main);
  transform: translateY(-1px);
}

.tool-icon-btn svg {
  width: 16px;
  height: 16px;
}

/* 紧随纸张右侧正中央的双联翻页条 (截图同款) */
.paper-aside-nav {
  position: absolute;
  left: calc(100% + 14px);
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  z-index: 88;
  border-radius: 4px;
  overflow: hidden;
  box-shadow: 0 1px 6px rgba(0, 0, 0, 0.04);
  user-select: none;
  background: rgba(0, 0, 0, 0.07);
}

body.theme-night .paper-aside-nav {
  background: rgba(255, 255, 255, 0.08);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.side-page-btn {
  width: 34px;
  height: 64px;
  background: rgba(0, 0, 0, 0.06);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.16s ease;
  color: var(--reader-muted);
  outline: none;
  padding: 0;
}

body.theme-night .side-page-btn {
  background: rgba(255, 255, 255, 0.06);
  color: #a8aab0;
}

.side-page-btn.btn-prev {
  border-bottom: 1px solid rgba(0, 0, 0, 0.07);
}

body.theme-night .side-page-btn.btn-prev {
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
}

.side-page-btn:hover {
  background: rgba(0, 0, 0, 0.14);
  color: var(--text-main);
}

body.theme-night .side-page-btn:hover {
  background: rgba(255, 255, 255, 0.15);
  color: #ffffff;
}

.side-page-btn:active {
  background: rgba(0, 0, 0, 0.22);
}

body.theme-night .side-page-btn:active {
  background: rgba(255, 255, 255, 0.26);
}

.nav-triangle-icon {
  width: 13px;
  height: 13px;
  fill: currentColor;
  opacity: 0.7;
  transition: transform 0.15s ease, opacity 0.15s;
}

.side-page-btn:hover .nav-triangle-icon {
  opacity: 1;
}

.side-page-btn.btn-prev:hover .nav-triangle-icon {
  transform: translateX(-2px);
}

.side-page-btn.btn-next:hover .nav-triangle-icon {
  transform: translateX(2px);
}

/* 屏幕较窄时自适应贴靠 */
@media (max-width: 960px) {
  .paper-aside-tools {
    left: auto;
    right: 8px;
    top: 12px;
    flex-direction: row;
  }
  .paper-aside-nav {
    left: auto;
    right: 8px;
  }
  .side-page-btn {
    width: 30px;
    height: 52px;
  }
}

/* 章节分页：新章节另起一页，首章除外 */
body.mode-paged .reader-chapter-section {
  margin-bottom: 0 !important;
  break-before: column;
  page-break-before: always;
}

body.mode-paged .reader-chapter-section:first-child {
  break-before: auto;
  page-break-before: auto;
}

/* 章节标题：截图同款左对齐，文雅轻盈，不居中不突兀 */
.chapter-header {
  text-align: left;
  margin: 6px 0 22px 0;
  break-inside: avoid;
  page-break-inside: avoid;
}

.chapter-number {
  display: none;
}

.chapter-title {
  font-family: var(--font-serif);
  font-size: 21px;
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: 0.04em;
  color: var(--text-main);
  margin: 0;
}

/* 正文排版：1:1 豆瓣阅读行高、字号与间距，提升每页信息量 */
.reader-content {
  font-family: var(--font-serif);
  font-size: 17px;
  line-height: 1.82;
  letter-spacing: normal;
  width: 100%;
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

.reader-content p {
  margin: 0 0 1.05em 0 !important;
  text-indent: 2em;
  text-align: justify;
  word-break: break-all;
  overflow-wrap: break-word;
  line-height: 1.82;
  max-width: 100%;
  box-sizing: border-box;
  padding-right: 2px;
  orphans: 1;
  widows: 1;
}

.reader-content blockquote {
  margin: 1.2em 0;
  padding: 8px 16px;
  border-left: 3px solid var(--brand-green);
  background: rgba(0, 0, 0, 0.02);
  font-style: italic;
  text-indent: 0;
  max-width: 100%;
  box-sizing: border-box;
}

.reader-content hr {
  border: none;
  border-top: 1px dashed var(--reader-border);
  margin: 2em auto;
  width: 50%;
}

body.mode-paged .chapter-footer-nav {
  break-before: column;
  page-break-before: always;
  margin-top: 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* ========================================================
   2. 垂直滚动模式 (mode-vertical)
   ======================================================== */
body.mode-vertical {
  height: auto !important;
  overflow-y: auto !important;
  position: relative !important;
}

body.mode-vertical .reader-viewport {
  margin: 40px auto 80px;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  box-sizing: border-box;
  overflow: visible;
  height: auto;
}

body.mode-vertical .reader-paper-sheet {
  margin: 0 auto;
  min-height: calc(100vh - 120px);
  height: auto !important;
  padding: 40px var(--paper-padding-x, 52px) 60px;
}

body.mode-vertical .reader-paper-sheet.width-normal {
  width: var(--paper-w, 780px);
  max-width: calc(100vw - 80px);
}

body.mode-vertical .reader-paper-sheet.width-wide {
  width: var(--paper-w, 920px);
  max-width: calc(100vw - 60px);
}

body.mode-vertical .reader-page-stage {
  height: auto !important;
  overflow: visible !important;
  width: 100% !important;
}

body.mode-vertical .reader-container {
  height: auto !important;
  width: 100% !important;
  column-width: auto !important;
  column-count: auto !important;
  column-gap: normal !important;
  transform: none !important;
}

body.mode-vertical .reader-page-foot,
body.mode-vertical .paper-bottom-progress {
  display: none !important;
}

body.mode-vertical .chapter-footer-nav {
  margin-top: 50px;
  padding-top: 30px;
  border-top: 1px solid var(--reader-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* 垂直模式下右侧翻页按钮固定在右侧视口 */
body.mode-vertical .paper-aside-nav {
  position: fixed;
  left: calc(50% + var(--paper-w, 780px) / 2 + 14px);
  top: 50%;
  transform: translateY(-50%);
}

body.mode-vertical .paper-aside-tools {
  position: fixed;
  left: calc(50% + var(--paper-w, 780px) / 2 + 14px);
  top: 50px;
}

@media (max-width: 960px) {
  body.mode-vertical .paper-aside-nav {
    left: auto;
    right: 8px;
  }
  body.mode-vertical .paper-aside-tools {
    left: auto;
    right: 8px;
    top: 12px;
  }
}

/* ========================================================
   三套字体族：楷体(默认)、宋体、黑体
   ======================================================== */
body.font-family-kai { --font-serif: var(--font-kai); font-family: var(--font-kai) !important; }
body.font-family-song { --font-serif: var(--font-song); font-family: var(--font-song) !important; }
body.font-family-hei { --font-serif: var(--font-hei); font-family: var(--font-hei) !important; }

body.font-family-kai .reader-content,
body.font-family-kai .chapter-title,
body.font-family-kai #runningHeadChapter,
body.font-family-kai #runningPageNumber,
body.font-family-kai .toc-item a {
  font-family: var(--font-kai) !important;
}

body.font-family-song .reader-content,
body.font-family-song .chapter-title,
body.font-family-song #runningHeadChapter,
body.font-family-song #runningPageNumber,
body.font-family-song .toc-item a {
  font-family: var(--font-song) !important;
}

body.font-family-hei .reader-content,
body.font-family-hei .chapter-title,
body.font-family-hei #runningHeadChapter,
body.font-family-hei #runningPageNumber,
body.font-family-hei .toc-item a {
  font-family: var(--font-hei) !important;
}

/* 字体档位控制 (默认 md 为 17px，紧凑高信息量) */
body.font-size-sm .reader-content { font-size: 15px; line-height: 1.8; }
body.font-size-md .reader-content { font-size: 17px; line-height: 1.82; }
body.font-size-lg .reader-content { font-size: 19px; line-height: 1.85; }
body.font-size-xl .reader-content { font-size: 22px; line-height: 1.9; }

/* 章节末尾切换按钮 */
.btn-chapter-nav {
  padding: 8px 18px;
  border: 1px solid var(--reader-border);
  border-radius: 4px;
  background: var(--reader-card);
  font-size: 13px;
  color: inherit;
  text-decoration: none;
  transition: all 0.2s;
}

.btn-chapter-nav:hover {
  border-color: var(--brand-green);
  color: var(--brand-green);
}

/* ========================================================
   底部 Dock 设置抽屉浮板：平时沉浸收敛，点击右上角设置唤出
   ======================================================== */
.reader-dock {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%) translateY(0);
  background: var(--bg-paper);
  border: 1px solid var(--reader-border);
  border-radius: 30px;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.12);
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 8px 20px;
  z-index: 90;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  opacity: 0.94;
}

.reader-dock:hover {
  opacity: 1;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.16);
}

.reader-dock.dock-hidden {
  transform: translateX(-50%) translateY(140%);
  opacity: 0;
  pointer-events: none;
}

.dock-btn {
  background: transparent;
  border: none;
  color: var(--reader-muted);
  font-size: 13px;
  cursor: pointer;
  padding: 6px 10px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  gap: 4px;
  transition: all 0.2s;
}

.dock-btn:hover {
  background: rgba(0, 0, 0, 0.06);
  color: inherit;
}

body.theme-night .dock-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.dock-divider {
  width: 1px;
  height: 18px;
  background: var(--reader-border);
}

/* 阅读模式切换按钮组 */
.read-mode-switch {
  display: flex;
  align-items: center;
  background: rgba(0, 0, 0, 0.05);
  border-radius: 14px;
  padding: 2px;
  gap: 2px;
}

body.theme-night .read-mode-switch {
  background: rgba(255, 255, 255, 0.08);
}

.mode-btn {
  background: transparent;
  border: none;
  font-size: 12px;
  padding: 4px 8px;
  border-radius: 10px;
  color: var(--reader-muted);
  cursor: pointer;
  transition: all 0.2s ease;
  line-height: 1;
  display: flex;
  align-items: center;
  gap: 3px;
}

.mode-btn:hover {
  color: inherit;
}

.mode-btn.active {
  background: var(--reader-card);
  color: var(--brand-green);
  font-weight: 700;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
}

body.theme-night .mode-btn.active {
  background: #2a2c31;
  color: #fff;
}

/* 字体切换按钮组 */
.font-family-switch {
  display: flex;
  align-items: center;
  background: rgba(0, 0, 0, 0.05);
  border-radius: 14px;
  padding: 2px;
  gap: 2px;
}

body.theme-night .font-family-switch {
  background: rgba(255, 255, 255, 0.08);
}

.font-btn {
  background: transparent;
  border: none;
  font-size: 12px;
  padding: 4px 8px;
  border-radius: 10px;
  color: var(--reader-muted);
  cursor: pointer;
  transition: all 0.2s ease;
  line-height: 1;
}

.font-btn:hover {
  color: inherit;
}

.font-btn.active {
  background: var(--reader-card);
  color: var(--brand-green);
  font-weight: 700;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
}

body.theme-night .font-btn.active {
  background: #2a2c31;
  color: #fff;
}

/* 主题颜色选择圆点 */
.theme-dots {
  display: flex;
  align-items: center;
  gap: 8px;
}

.theme-dot {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.2s, border-color 0.2s;
}

.theme-dot:hover {
  transform: scale(1.15);
}

.theme-dot.active {
  border-color: var(--brand-green);
  transform: scale(1.1);
}

.dot-paper { background: #f8f6f2; border: 1px solid #ccc; }
.dot-eye { background: #eaf1e9; }
.dot-parchment { background: #f4ecdf; }
.dot-night { background: #18191c; border: 1px solid #444; }

/* ========================================================
   目录抽屉面板 (TOC Drawer)
   ======================================================== */
.toc-drawer-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  z-index: 150;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.toc-drawer-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.toc-drawer {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 320px;
  max-width: 85vw;
  background: var(--reader-card);
  border-right: 1px solid var(--reader-border);
  z-index: 160;
  transform: translateX(-100%);
  transition: transform 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
  display: flex;
  flex-direction: column;
}

.toc-drawer.open {
  transform: translateX(0);
}

.toc-header {
  padding: 18px 20px;
  border-bottom: 1px solid var(--reader-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.toc-header h3 {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
  margin: 0;
}

.toc-close {
  background: transparent;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--reader-muted);
}

.toc-list {
  flex: 1;
  overflow-y: auto;
  padding: 12px 0;
  list-style: none;
  margin: 0;
}

.toc-item a {
  display: block;
  padding: 12px 20px;
  font-size: 14px;
  color: inherit;
  text-decoration: none;
  transition: background 0.15s;
  border-left: 3px solid transparent;
}

.toc-item a:hover {
  background: rgba(0, 0, 0, 0.04);
}

.toc-item.active a {
  border-left-color: var(--brand-green);
  color: var(--brand-green);
  font-weight: 600;
  background: rgba(56, 118, 66, 0.06);
}

/* 进度恢复通知浮条 */
.progress-toast {
  position: fixed;
  top: 70px;
  right: 24px;
  background: var(--reader-card);
  border: 1px solid var(--brand-green);
  color: inherit;
  padding: 10px 18px;
  border-radius: 6px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.1);
  font-size: 13px;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 10px;
  transform: translateY(-20px);
  opacity: 0;
  transition: all 0.3s ease;
  pointer-events: none;
}

.progress-toast.show {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

/* ========================================================
   移动端与触屏体验优化 (Mobile & Touch Interaction Overhauls)
   基于 Modern Web Guidance 规范落地：
   1. Dynamic Viewport (100dvh) 防止移动端地址栏弹缩时内容抖动
   2. Safe Area Insets (全面适配 iPhone 灵动岛 / 底部横条与挖孔屏)
   3. 移动端全宽纯净纸张排版与大触控热区
   ======================================================== */
.reader-body {
  min-height: 100vh;
  min-height: 100dvh;
  padding-top: env(safe-area-inset-top, 0px);
  padding-bottom: env(safe-area-inset-bottom, 0px);
  padding-left: env(safe-area-inset-left, 0px);
  padding-right: env(safe-area-inset-right, 0px);
}

.reader-viewport {
  height: 100vh;
  height: 100dvh;
}

@media (max-width: 768px) {
  html, body {
    overflow-x: hidden !important;
    max-width: 100vw !important;
    width: 100% !important;
  }

  .reader-viewport {
    width: 100% !important;
    max-width: 100% !important;
    overflow-x: hidden !important;
  }

  :root {
    --paper-w: 100%;
    --paper-padding-x: 16px;
    --page-stage-gap: 32px;
  }

  body.width-normal,
  body.width-wide {
    --paper-w: 100%;
    --paper-padding-x: 16px;
    --stage-inner-w: calc(100% - 32px);
    --stage-col-w: calc(100% - 32px);
  }

  /* 移动端纸张边缘取消阴影与外边距，最大化阅读视界，严格防溢出 */
  .reader-paper-sheet {
    width: 100% !important;
    max-width: 100% !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    padding: 14px 16px 10px 16px !important;
    box-sizing: border-box !important;
    overflow-x: hidden !important;
  }

  .reader-top-left-back {
    left: 14px;
    top: calc(12px + env(safe-area-inset-top, 0px));
    padding: 6px 12px;
    font-size: 13px;
    z-index: 99;
  }

  .paper-aside-tools {
    top: calc(10px + env(safe-area-inset-top, 0px));
    right: 14px;
    z-index: 99;
  }

  .tool-icon-btn {
    width: 38px;
    height: 38px;
  }

  /* 移动端以手势和点击为主，隐藏浮动翻页条 */
  .paper-aside-nav {
    display: none !important;
  }

  .reader-content {
    font-size: 18px; /* 移动端字号略微调大，极佳护眼易读 */
    line-height: 1.85;
    word-break: break-word !important;
    overflow-wrap: break-word !important;
  }

  .reader-content p {
    text-indent: 2em;
    margin-bottom: 0.95em !important;
    word-break: break-word !important;
    overflow-wrap: break-word !important;
  }

  /* 底部 Dock 弹性适应，层级高于常规悬浮浮标，并避让 iPhone 底部横条与吸底广告 */
  .reader-dock {
    width: calc(100% - 24px) !important;
    max-width: 440px !important;
    bottom: calc(12px + env(safe-area-inset-bottom, 0px)) !important;
    padding: 8px 12px !important;
    gap: 6px !important;
    justify-content: space-around;
    z-index: 100000 !important;
  }

  /* 若页面激活了底部常驻广告横幅，Dock 智能上浮避让，防止被死死遮挡 */
  body:has(#mobileStickyAdBar) .reader-dock {
    bottom: calc(64px + env(safe-area-inset-bottom, 0px)) !important;
  }

  .dock-btn {
    padding: 6px 8px;
    font-size: 12px;
  }

  /* 目录抽屉顶部与底部安全边距 */
  .toc-drawer {
    padding-top: env(safe-area-inset-top, 0px);
    padding-bottom: env(safe-area-inset-bottom, 0px);
  }
}

@media (max-width: 480px) {
  :root {
    --paper-padding-x: 16px;
  }

  .reader-paper-sheet {
    padding: 10px 16px 8px 16px !important;
  }

  .chapter-title {
    font-size: 19px;
  }

  .reader-dock {
    gap: 4px !important;
    padding: 6px 10px !important;
  }

  .dock-btn {
    font-size: 11px;
    padding: 5px 6px;
  }
}