/**
 * Next-Gen Blog Styles v2
 * 下一代博客创新功能样式 - 增强视觉与布局优化
 */

/* ==================== CSS 变量 ==================== */
:root {
  --article-font-size: 16px;
  --article-line-height: 1.8;
  --ng-accent: #c25e00;
  --ng-accent-light: #e8a87c;
  --ng-accent-soft: rgba(194, 94, 0, 0.08);
  --ng-bg: #faf9f6;
  --ng-ink: #2c2c2c;
  --ng-muted: #6b6b6b;
  --ng-rule: #d4d4d4;
  --ng-shadow: 0 2px 12px rgba(0,0,0,0.08);
  --ng-shadow-hover: 0 4px 20px rgba(0,0,0,0.12);
  --ng-radius: 12px;
  --ng-radius-sm: 8px;
}

/* ==================== 1. 阅读进度条 ==================== */
.reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: rgba(0,0,0,0.05);
  z-index: 9999;
  pointer-events: none;
}

.reading-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--ng-accent), var(--ng-accent-light));
  width: 0%;
  transition: width 0.1s ease-out;
}

.reading-percentage {
  position: fixed;
  top: 12px;
  right: 12px;
  background: var(--ng-accent);
  color: white;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
  z-index: 9999;
  opacity: 0;
  transition: opacity 0.3s;
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  box-shadow: var(--ng-shadow);
}

/* ==================== 2. 沉浸式阅读模式 ==================== */
.immersive-reader-btn {
  position: fixed;
  bottom: 160px;
  right: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: none;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  cursor: pointer;
  font-size: 20px;
  z-index: 1000;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
}

.immersive-reader-btn:hover {
  transform: scale(1.15) rotate(5deg);
  box-shadow: 0 6px 25px rgba(102, 126, 234, 0.5);
}

.immersive-reader-btn:active {
  transform: scale(0.95);
}

body.immersive-mode .paper-main,
body.immersive-mode .post-main {
  max-width: 720px !important;
  margin: 0 auto;
  padding: 50px 70px;
  background: var(--ng-bg);
  box-shadow: 0 0 80px rgba(0,0,0,0.08);
  border-radius: var(--ng-radius);
}

body.immersive-mode .header,
body.immersive-mode .footer,
body.immersive-mode .post-footer-pre-next,
body.immersive-mode .post-meta,
body.immersive-mode .smart-toc-container,
body.immersive-mode .floating-toolbar,
body.immersive-mode .progress-wrap,
body.immersive-mode .return-to-last-progress-wrap {
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.5s ease;
}

body.immersive-mode {
  background: #e8e6e1 !important;
}

.reader-toast {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.9);
  background: var(--ng-ink);
  color: white;
  padding: 14px 28px;
  border-radius: var(--ng-radius-sm);
  font-size: 14px;
  z-index: 10000;
  opacity: 0;
  transition: all 0.3s ease;
  pointer-events: none;
  box-shadow: var(--ng-shadow-hover);
}

.reader-toast.show {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}

/* ==================== 3. 浮动工具栏（整合所有按钮）==================== */
.floating-toolbar {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: center;
}

.ft-main-btn {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  border: none;
  background: linear-gradient(135deg, var(--ng-accent) 0%, var(--ng-accent-light) 100%);
  color: white;
  cursor: pointer;
  font-size: 22px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 15px rgba(194, 94, 0, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.ft-main-btn:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 25px rgba(194, 94, 0, 0.45);
}

.ft-main-btn.active {
  transform: rotate(45deg);
}

.ft-menu {
  display: flex;
  flex-direction: column;
  gap: 8px;
  opacity: 0;
  transform: translateY(20px) scale(0.8);
  pointer-events: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.ft-menu.show {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: all;
}

.ft-item {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--ng-rule);
  background: var(--ng-bg);
  cursor: pointer;
  font-size: 18px;
  transition: all 0.2s ease;
  box-shadow: var(--ng-shadow);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.ft-item:hover {
  transform: scale(1.15);
  box-shadow: var(--ng-shadow-hover);
  border-color: var(--ng-accent);
}

.ft-item::after {
  content: attr(data-label);
  position: absolute;
  right: 55px;
  background: var(--ng-ink);
  color: white;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 12px;
  white-space: nowrap;
  opacity: 0;
  transform: translateX(10px);
  transition: all 0.2s ease;
  pointer-events: none;
}

.ft-item:hover::after {
  opacity: 1;
  transform: translateX(0);
}

/* ==================== 4. 智能目录 ==================== */
.smart-toc-container {
  position: fixed;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 999;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.smart-toc-toggle {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--ng-rule);
  background: var(--ng-bg);
  cursor: pointer;
  font-size: 16px;
  transition: all 0.3s;
  box-shadow: var(--ng-shadow);
  display: flex;
  align-items: center;
  justify-content: center;
}

.smart-toc-toggle:hover {
  border-color: var(--ng-accent);
  color: var(--ng-accent);
}

.smart-toc {
  background: var(--ng-bg);
  border: 1px solid var(--ng-rule);
  border-radius: var(--ng-radius-sm);
  padding: 14px 0;
  max-height: 60vh;
  overflow-y: auto;
  width: 240px;
  box-shadow: var(--ng-shadow);
  transition: all 0.3s ease;
}

.smart-toc.collapsed {
  opacity: 0;
  transform: translateX(20px);
  pointer-events: none;
}

.smart-toc-header {
  font-weight: 600;
  font-size: 13px;
  padding: 0 18px 10px;
  border-bottom: 1px solid var(--ng-rule);
  margin-bottom: 10px;
  color: var(--ng-muted);
  display: flex;
  align-items: center;
  gap: 6px;
}

.smart-toc-header::before {
  content: '📑';
  font-size: 14px;
}

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

.smart-toc-item {
  margin: 0;
  padding: 0;
}

.smart-toc-item a {
  display: block;
  padding: 6px 18px;
  font-size: 13px;
  color: var(--ng-muted);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: all 0.2s;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.smart-toc-item.level-2 a { padding-left: 18px; }
.smart-toc-item.level-3 a { padding-left: 32px; font-size: 12px; }
.smart-toc-item.level-4 a { padding-left: 46px; font-size: 11px; }

.smart-toc-item a:hover {
  color: var(--ng-accent);
  background: var(--ng-accent-soft);
}

.smart-toc-item.active a {
  color: var(--ng-accent);
  border-left-color: var(--ng-accent);
  background: var(--ng-accent-soft);
  font-weight: 500;
}

@media (max-width: 1200px) {
  .smart-toc-container { display: none; }
}

/* ==================== 5. 知识图谱 ==================== */
.knowledge-graph-widget {
  margin: 28px 0;
  border: 1px solid var(--ng-rule);
  border-radius: var(--ng-radius-sm);
  overflow: hidden;
  background: var(--ng-bg);
  box-shadow: var(--ng-shadow);
}

.kg-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 18px;
  background: linear-gradient(135deg, var(--ng-accent-soft), transparent);
  border-bottom: 1px solid var(--ng-rule);
  font-size: 14px;
  font-weight: 600;
  color: var(--ng-accent);
}

.kg-header::before {
  content: '🔗';
  margin-right: 6px;
}

.kg-toggle {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 12px;
  color: var(--ng-muted);
  padding: 4px;
  transition: transform 0.2s;
}

.kg-toggle:hover {
  transform: scale(1.2);
}

.kg-content {
  padding: 14px 18px;
  transition: all 0.3s;
}

.kg-content.collapsed {
  display: none;
}

.kg-nodes {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.kg-node {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 5px 14px;
  border-radius: 20px;
  font-size: 13px;
  text-decoration: none;
  transition: all 0.2s;
  border: 1px solid transparent;
}

.kg-node:hover {
  transform: translateY(-2px);
  box-shadow: var(--ng-shadow);
}

.kg-node::before {
  font-size: 12px;
}

.kg-tag {
  background: #e3f2fd;
  color: #1565c0;
  border-color: #bbdefb;
}
.kg-tag::before { content: '🏷️'; }

.kg-category {
  background: #f3e5f5;
  color: #6a1b9a;
  border-color: #e1bee7;
}
.kg-category::before { content: '📂'; }

.kg-article {
  background: #e8f5e9;
  color: #2e7d32;
  border-color: #c8e6c9;
}
.kg-article::before { content: '📄'; }

/* ==================== 6. 主题设置面板 ==================== */
.theme-settings-panel {
  position: fixed;
  bottom: 100px;
  right: 24px;
  width: 300px;
  background: var(--ng-bg);
  border: 1px solid var(--ng-rule);
  border-radius: var(--ng-radius);
  padding: 24px;
  z-index: 1001;
  box-shadow: 0 8px 40px rgba(0,0,0,0.15);
  opacity: 0;
  transform: translateY(20px) scale(0.9);
  pointer-events: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.theme-settings-panel.show {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: all;
}

.ts-header {
  font-weight: 700;
  font-size: 16px;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--ng-accent);
  color: var(--ng-accent);
  display: flex;
  align-items: center;
  gap: 8px;
}

.ts-header::before {
  content: '🎨';
}

.ts-section {
  margin-bottom: 20px;
}

.ts-label {
  font-size: 12px;
  color: var(--ng-muted);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  font-weight: 600;
}

.ts-options {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.ts-options button {
  flex: 1;
  min-width: 60px;
  padding: 8px 12px;
  border: 2px solid var(--ng-rule);
  background: transparent;
  border-radius: var(--ng-radius-sm);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
}

.ts-options button:hover {
  border-color: var(--ng-accent);
  color: var(--ng-accent);
  background: var(--ng-accent-soft);
}

.ts-options button.active {
  background: var(--ng-accent);
  color: white;
  border-color: var(--ng-accent);
}

.ts-section input[type="range"] {
  width: 100%;
  margin-top: 6px;
  -webkit-appearance: none;
  height: 6px;
  border-radius: 3px;
  background: var(--ng-rule);
  outline: none;
}

.ts-section input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--ng-accent);
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(194, 94, 0, 0.3);
}

.font-size-value,
.line-height-value {
  color: var(--ng-accent);
  font-weight: 700;
}

/* 字体主题 */
body[data-font="serif"] .post-md,
body[data-font="serif"] .paper-main {
  font-family: "Noto Serif CJK SC", "Source Han Serif SC", "SimSun", serif;
}

body[data-font="sans"] .post-md,
body[data-font="sans"] .paper-main {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body[data-font="mono"] .post-md,
body[data-font="mono"] .paper-main {
  font-family: "JetBrains Mono", "Fira Code", monospace;
}

/* 颜色主题 */
body[data-theme="dark"] {
  --ng-bg: #1a1a1a;
  --ng-ink: #e0e0e0;
  --ng-muted: #888;
  --ng-rule: #333;
}

body[data-theme="dark"] .paper,
body[data-theme="dark"] .paper-main {
  background: #1e1e1e !important;
  color: #e0e0e0 !important;
}

body[data-theme="sepia"] {
  --ng-bg: #f4ecd8;
  --ng-ink: #5b4636;
}

body[data-theme="sepia"] .paper,
body[data-theme="sepia"] .paper-main {
  background: #f4ecd8 !important;
  color: #5b4636 !important;
}

body[data-theme="green"] {
  --ng-bg: #e8f5e9;
  --ng-ink: #1b5e20;
}

body[data-theme="green"] .paper,
body[data-theme="green"] .paper-main {
  background: #e8f5e9 !important;
  color: #1b5e20 !important;
}

/* ==================== 7. 阅读分析器 ==================== */
.reading-analyzer {
  margin: 20px 0 28px;
  padding: 20px;
  background: linear-gradient(135deg, var(--ng-accent-soft), rgba(194, 94, 0, 0.02));
  border-radius: var(--ng-radius-sm);
  border: 1px solid rgba(194, 94, 0, 0.15);
  box-shadow: var(--ng-shadow);
}

.ra-header {
  font-size: 14px;
  font-weight: 700;
  color: var(--ng-accent);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.ra-header::before {
  content: '📊';
}

.ra-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-bottom: 16px;
}

.ra-stat {
  text-align: center;
  padding: 10px;
  background: rgba(255,255,255,0.5);
  border-radius: var(--ng-radius-sm);
}

.ra-value {
  display: block;
  font-size: 22px;
  font-weight: 700;
  color: var(--ng-accent);
  line-height: 1.2;
}

.ra-value.easy { color: #2e7d32; }
.ra-value.medium { color: #ef6c00; }
.ra-value.hard { color: #c62828; }

.ra-label {
  font-size: 11px;
  color: var(--ng-muted);
  margin-top: 4px;
}

.ra-detail {
  display: flex;
  align-items: center;
  gap: 12px;
}

.ra-bar {
  flex: 1;
  height: 8px;
  background: var(--ng-rule);
  border-radius: 4px;
  overflow: hidden;
}

.ra-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--ng-accent), var(--ng-accent-light));
  border-radius: 4px;
  transition: width 0.8s ease;
}

.ra-bar-label {
  font-size: 12px;
  color: var(--ng-muted);
  white-space: nowrap;
  font-weight: 500;
}

@media (max-width: 600px) {
  .ra-stats { grid-template-columns: repeat(2, 1fr); }
}

/* ==================== 8. 代码块增强 ==================== */
.code-block-wrapper {
  margin: 20px 0;
  border-radius: var(--ng-radius-sm);
  overflow: hidden;
  border: 1px solid var(--ng-rule);
  box-shadow: var(--ng-shadow);
}

.code-block-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 18px;
  background: linear-gradient(135deg, #f5f5f5, #fafafa);
  border-bottom: 1px solid var(--ng-rule);
}

.code-lang {
  font-size: 12px;
  color: var(--ng-muted);
  font-family: "JetBrains Mono", monospace;
  text-transform: uppercase;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 6px;
}

.code-lang::before {
  content: '◆';
  color: var(--ng-accent);
  font-size: 10px;
}

.code-copy-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border: 1px solid var(--ng-rule);
  background: white;
  border-radius: 6px;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.2s;
  color: var(--ng-muted);
  font-weight: 500;
}

.code-copy-btn:hover {
  border-color: var(--ng-accent);
  color: var(--ng-accent);
  background: var(--ng-accent-soft);
}

.code-copy-btn.copied {
  background: #e8f5e9;
  border-color: #2e7d32;
  color: #2e7d32;
}

.code-block-wrapper pre {
  margin: 0 !important;
  border-radius: 0 !important;
}

/* ==================== 9. 图片灯箱 ==================== */
.image-lightbox {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.image-lightbox.show {
  opacity: 1;
}

.lightbox-backdrop {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.92);
  backdrop-filter: blur(10px);
}

.lightbox-img {
  position: relative;
  max-width: 90%;
  max-height: 90%;
  object-fit: contain;
  border-radius: var(--ng-radius-sm);
  transform: scale(0.9);
  transition: transform 0.3s ease;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}

.image-lightbox.show .lightbox-img {
  transform: scale(1);
}

.lightbox-close {
  position: absolute;
  top: 24px;
  right: 24px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,0.2);
  background: rgba(255,255,255,0.1);
  color: white;
  font-size: 20px;
  cursor: pointer;
  z-index: 1;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.lightbox-close:hover {
  background: rgba(255,255,255,0.2);
  transform: scale(1.1);
}

/* ==================== 10. 文章装饰元素 ==================== */
.post-md {
  font-size: var(--article-font-size);
  line-height: var(--article-line-height);
}

.post-md p {
  margin-bottom: calc(var(--article-font-size) * var(--article-line-height) * 0.6);
}

/* 引用块装饰 */
.post-md blockquote {
  border-left: 4px solid var(--ng-accent);
  background: linear-gradient(135deg, var(--ng-accent-soft), transparent);
  padding: 16px 20px;
  margin: 20px 0;
  border-radius: 0 var(--ng-radius-sm) var(--ng-radius-sm) 0;
  font-style: italic;
  position: relative;
}

.post-md blockquote::before {
  content: '"';
  position: absolute;
  top: 8px;
  left: 12px;
  font-size: 48px;
  color: var(--ng-accent-light);
  opacity: 0.3;
  font-family: Georgia, serif;
  line-height: 1;
}

/* 分隔线装饰 */
.post-md hr {
  border: none;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--ng-accent-light), transparent);
  margin: 32px 0;
  position: relative;
}

.post-md hr::after {
  content: '✦';
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background: var(--ng-bg);
  padding: 0 12px;
  color: var(--ng-accent);
  font-size: 14px;
}

/* 表格装饰 */
.post-md table {
  border-collapse: collapse;
  width: 100%;
  margin: 20px 0;
  border-radius: var(--ng-radius-sm);
  overflow: hidden;
  box-shadow: var(--ng-shadow);
}

.post-md th {
  background: linear-gradient(135deg, var(--ng-accent), var(--ng-accent-light));
  color: white;
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
}

.post-md td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--ng-rule);
}

.post-md tr:nth-child(even) {
  background: var(--ng-accent-soft);
}

.post-md tr:hover {
  background: rgba(194, 94, 0, 0.12);
}

/* 列表装饰 */
.post-md ul li::marker {
  color: var(--ng-accent);
}

.post-md ol li::marker {
  color: var(--ng-accent);
  font-weight: 600;
}

/* 链接装饰 */
.post-md a {
  color: var(--ng-accent);
  text-decoration: none;
  border-bottom: 1px dashed var(--ng-accent-light);
  transition: all 0.2s;
}

.post-md a:hover {
  border-bottom-style: solid;
  background: var(--ng-accent-soft);
  padding: 0 2px;
  border-radius: 2px;
}

/* 标题装饰 */
.post-md h2 {
  position: relative;
  padding-bottom: 8px;
  margin-top: 36px;
}

.post-md h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--ng-accent), var(--ng-accent-light));
  border-radius: 2px;
}

.post-md h3 {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 28px;
}

.post-md h3::before {
  content: '';
  width: 6px;
  height: 6px;
  background: var(--ng-accent);
  border-radius: 50%;
}

/* ==================== 11. 文章推荐 ==================== */
.article-recommend {
  margin: 32px 0;
  padding: 24px;
  background: linear-gradient(135deg, rgba(194,94,0,0.03), rgba(194,94,0,0.08));
  border-radius: var(--ng-radius);
  border: 1px solid rgba(194,94,0,0.1);
}

.ar-header {
  font-size: 16px;
  font-weight: 700;
  color: var(--ng-accent);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.ar-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.ar-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: var(--ng-bg);
  border-radius: var(--ng-radius-sm);
  text-decoration: none;
  color: var(--ng-ink);
  border: 1px solid var(--ng-rule);
  transition: all 0.2s;
}

.ar-item:hover {
  border-color: var(--ng-accent);
  background: var(--ng-accent-soft);
  transform: translateX(4px);
}

.ar-title {
  font-size: 14px;
  font-weight: 500;
}

.ar-arrow {
  color: var(--ng-accent);
  font-size: 18px;
  transition: transform 0.2s;
}

.ar-item:hover .ar-arrow {
  transform: translateX(4px);
}

/* ==================== 12. 粒子背景 ==================== */
.particle-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
}

/* ==================== 13. 打字机光标 ==================== */
.post-main-title::after,
.index-header h1::after {
  content: '|';
  animation: blink 1s infinite;
  color: var(--ng-accent);
  margin-left: 2px;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

/* ==================== 14. 响应式优化 ==================== */
@media (max-width: 768px) {
  .floating-toolbar {
    bottom: 16px;
    right: 16px;
  }
  
  .ft-main-btn {
    width: 48px;
    height: 48px;
  }
  
  .theme-settings-panel {
    width: calc(100vw - 32px);
    right: 16px;
    left: 16px;
    bottom: 80px;
  }
  
  .immersive-reader-btn {
    bottom: 140px;
    right: 16px;
  }
  
  .smart-toc-container {
    display: none;
  }
  
  .reading-analyzer {
    padding: 16px;
  }
  
  .ra-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }
}