```css
/* ==========================================================
   老司机漫画 - 完整样式表
   风格：暗色科技感 + 紫色渐变 + 毛玻璃效果
   响应式：全面适配PC/平板/手机
   ========================================================== */

/* ---------- CSS 变量 ---------- */
:root {
  --bg-primary: #0a0a18;
  --bg-secondary: #14142e;
  --bg-card: #1a1a35;
  --bg-card-hover: #1f1f42;
  --border-color: #2d2d55;
  --text-primary: #f0f0ff;
  --text-secondary: #d0d0e8;
  --text-muted: #8888aa;
  --accent: #8b5cf6;
  --accent-light: #a78bfa;
  --accent-gradient: linear-gradient(135deg, #7c3aed 0%, #6d28d9 100%);
  --glass-bg: rgba(20, 20, 46, 0.7);
  --glass-border: rgba(139, 92, 246, 0.2);
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-hover: 0 8px 30px rgba(139, 92, 246, 0.25);
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

/* ---------- 基础重置与全局 ---------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

ul, ol {
  list-style: none;
}

/* ---------- 滚动条美化 ---------- */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--accent);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-light);
}

/* ---------- 动画关键帧 ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes glowPulse {
  0%, 100% {
    box-shadow: 0 0 20px rgba(139, 92, 246, 0.3);
  }
  50% {
    box-shadow: 0 0 40px rgba(139, 92, 246, 0.6);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

/* ---------- 头部导航 ---------- */
header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  padding: 0 5%;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

header nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1400px;
  margin: 0 auto;
  flex-wrap: wrap;
  padding: 15px 0;
}

header h1 {
  color: var(--text-primary);
  font-size: 1.8em;
  margin: 0;
  background: linear-gradient(90deg, #7c3aed, #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 900;
  letter-spacing: 1px;
  animation: fadeIn 0.8s ease;
}

header nav > div {
  display: flex;
  gap: 25px;
  flex-wrap: wrap;
  align-items: center;
}

header nav a {
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
  padding: 5px 0;
}

header nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-gradient);
  transition: var(--transition);
  border-radius: 2px;
}

header nav a:hover {
  color: var(--accent-light);
  text-shadow: 0 0 10px rgba(139, 92, 246, 0.3);
}

header nav a:hover::after {
  width: 100%;
}

/* ---------- 主内容区域 ---------- */
main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 30px 5%;
}

main > div {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 30px;
  align-items: start;
}

main > div > div:first-child {
  min-width: 0;
}

/* ---------- 通用区块标题 ---------- */
section h2 {
  color: var(--text-primary);
  font-size: 2em;
  border-left: 4px solid var(--accent);
  padding-left: 15px;
  margin-bottom: 25px;
  animation: slideInLeft 0.6s ease;
  position: relative;
}

section h2::after {
  content: '';
  position: absolute;
  left: 15px;
  bottom: -5px;
  width: 50px;
  height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
}

/* ---------- 热门漫画卡片 ---------- */
#hot > div {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 25px;
}

#hot article {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  cursor: pointer;
  animation: fadeInUp 0.6s ease;
  position: relative;
}

#hot article:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: var(--shadow-hover);
  border-color: var(--accent);
}

#hot article img {
  width: 100%;
  height: auto;
  display: block;
  transition: var(--transition);
}

#hot article:hover img {
  transform: scale(1.05);
}

#hot article > div {
  padding: 15px;
  background: linear-gradient(to top, var(--bg-card) 80%, transparent);
}

#hot article h3 {
  color: var(--text-primary);
  margin: 0 0 8px 0;
  font-size: 1.1em;
  transition: var(--transition);
}

#hot article:hover h3 {
  color: var(--accent-light);
}

#hot article p {
  color: var(--text-secondary);
  margin: 5px 0;
  font-size: 0.9em;
}

#hot article p span {
  color: var(--accent-light);
}

#hot article span[style*="background"] {
  display: inline-block;
  background: rgba(139, 92, 246, 0.2) !important;
  color: var(--accent-light) !important;
  padding: 4px 12px !important;
  border-radius: 20px !important;
  font-size: 0.8em !important;
  margin-top: 8px !important;
  transition: var(--transition);
}

#hot article:hover span[style*="background"] {
  background: rgba(139, 92, 246, 0.4) !important;
  transform: scale(1.05);
}

/* ---------- 精品推荐卡片 ---------- */
#recommend > div {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 30px;
}

#recommend article {
  background: var(--bg-card-hover);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  cursor: pointer;
  animation: fadeInUp 0.6s ease;
}

#recommend article:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-hover);
  border-color: var(--accent);
}

#recommend article img {
  width: 100%;
  height: auto;
  display: block;
  transition: var(--transition);
}

#recommend article:hover img {
  transform: scale(1.03);
}

#recommend article > div {
  padding: 20px;
}

#recommend article h3 {
  color: var(--text-primary);
  margin: 0 0 10px 0;
  font-size: 1.2em;
  transition: var(--transition);
}

#recommend article:hover h3 {
  color: var(--accent-light);
}

#recommend article p {
  color: var(--text-secondary);
  margin: 0 0 10px 0;
  font-size: 0.95em;
}

#recommend article p span {
  color: var(--accent-light);
}

#recommend article p:last-child {
  margin: 0;
  font-size: 0.9em;
  line-height: 1.6;
  color: var(--text-secondary);
}

/* ---------- 漫画详细介绍 ---------- */
#detail {
  margin-bottom: 50px;
  background: var(--bg-secondary);
  padding: 30px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  animation: fadeInUp 0.6s ease;
  position: relative;
  overflow: hidden;
}

#detail::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
}

#detail article {
  color: var(--text-secondary);
  font-size: 1em;
  line-height: 1.9;
}

#detail h3 {
  color: var(--text-primary);
  font-size: 1.4em;
  margin-top: 25px;
  margin-bottom: 10px;
  position: relative;
  padding-left: 15px;
}

#detail h3::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 20px;
  background: var(--accent-gradient);
  border-radius: 2px;
}

#detail p {
  margin-bottom: 15px;
}

#detail p:last-child {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 15px;
}

#detail p span[style*="background"] {
  background: rgba(139, 92, 246, 0.2) !important;
  color: var(--accent-light) !important;
  padding: 5px 15px !important;
  border-radius: 20px !important;
  font-size: 0.9em !important;
  transition: var(--transition);
  cursor: pointer;
}

#detail p span[style*="background"]:hover {
  background: rgba(139, 92, 246, 0.4) !important;
  transform: scale(1.05);
}

/* ---------- 角色介绍 ---------- */
#characters > div {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 25px;
}

#characters article {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  text-align: center;
  transition: var(--transition);
  cursor: pointer;
  animation: fadeInUp 0.6s ease;
}

#characters article:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
  border-color: var(--accent);
}

#characters article img {
  border-radius: 50% !important;
  border: 3px solid var(--accent) !important;
  width: 150px !important;
  height: 150px !important;
  object-fit: cover !important;
  margin-bottom: 15px !important;
  transition: var(--transition);
}

#characters article:hover img {
  transform: scale(1.05);
  border-color: var(--accent-light) !important;
}

#characters article h3 {
  color: var(--text-primary);
  margin: 0 0 5px 0;
  font-size: 1.2em;
}

#characters article p {
  margin: 5px 0;
  font-size: 0.9em;
}

#characters article p:first-of-type {
  color: var(--accent-light);
}

#characters article p:last-child {
  margin-top: 10px;
  font-size: 0.85em;
  line-height: 1.5;
  color: var(--text-secondary);
}

/* ---------- 平台介绍 ---------- */
#platform {
  margin-bottom: 50px;
  background: var(--bg-secondary);
  padding: 40px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  animation: fadeInUp 0.6s ease;
  position: relative;
  overflow: hidden;
}

#platform::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
}

#platform > div {
  color: var(--text-secondary);
  font-size: 1em;
  line-height: 1.9;
}

#platform h3 {
  color: var(--text-primary);
  font-size: 1.4em;
  margin-top: 25px;
  margin-bottom: 10px;
  position: relative;
  padding-left: 15px;
}

#platform h3::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 20px;
  background: var(--accent-gradient);
  border-radius: 2px;
}

#platform p {
  margin-bottom: 15px;
}

/* ---------- APP 下载区域 ---------- */
#app {
  margin-bottom: 50px;
  text-align: center;
  background: var(--bg-card);
  padding: 50px 30px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  position: relative;
  overflow: hidden;
  animation: fadeInUp 0.6s ease;
}

#app::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
}

#app h2 {
  color: var(--text-primary);
  font-size: 2em;
  margin-bottom: 15px;
  border: none;
  padding: 0;
}

#app h2::after {
  display: none;
}

#app p {
  color: var(--text-secondary);
  font-size: 1.1em;
  max-width: 600px;
  margin: 0 auto 30px auto;
}

#app > div {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

#app a {
  display: inline-block;
  background: var(--accent-gradient);
  color: #ffffff;
  padding: 15px 40px;
  border-radius: 50px;
  text-decoration: none;
  font-size: 1.1em;
  font-weight: bold;
  transition: var(--transition);
  box-shadow: 0 4px 15px rgba(124, 58, 237, 0.4);
  position: relative;
  overflow: hidden;
}

#app a::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: var(--transition);
}

#app a:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 25px rgba(124, 58, 237, 0.6);
  animation: glowPulse 2s infinite;
}

#app a:hover::before {
  left: 100%;
}

/* ---------- 用户评论 ---------- */
#reviews > div {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

#reviews article {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: var(--transition);
  animation: fadeInUp 0.6s ease;
  position: relative;
}

#reviews article::before {
  content: '"';
  position: absolute;
  top: 10px;
  right: 20px;
  font-size: 3em;
  color: var(--accent);
  opacity: 0.2;
  font-family: Georgia, serif;
}

#reviews article:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
  border-color: var(--accent);
}

#reviews article p:first-child {
  color: var(--accent-light);
  font-weight: bold;
  margin: 0 0 5px 0;
}

#reviews article p:nth-child(2) {
  color: var(--text-muted);
  font-size: 0.8em;
  margin: 0 0 10px 0;
}

#reviews article p:last-child {
  color: var(--text-secondary);
  margin: 0;
  font-size: 0.9em;
  line-height: 1.6;
}

/* ---------- 侧边栏 ---------- */
aside {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 25px;
  position: sticky;
  top: 80px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  animation: slideInRight 0.6s ease;
}

aside h2 {
  color: var(--text-primary);
  font-size: 1.5em;
  border-bottom: 2px solid var(--accent);
  padding-bottom: 10px;
  margin-bottom: 20px;
}

aside h3 {
  color: var(--text-primary);
  font-size: 1.1em;
  margin-bottom: 15px;
}

aside ol,
aside ul {
  color: var(--text-secondary);
  padding-left: 0;
  margin: 0;
  list-style: none;
}

aside ol li,
aside ul li {
  margin-bottom: 10px;
  padding: 8px;
  background: rgba(139, 92, 246, 0.1);
  border-radius: var(--radius-sm);
  transition: var(--transition);
  cursor: pointer;
}

aside ol li:hover,
aside ul li:hover {
  background: rgba(139, 92, 246, 0.2);
  transform: translateX(5px);
}

aside ol li span {
  color: var(--accent-light);
  font-weight: bold;
}

aside ul li span {
  color: var(--accent-light);
  float: right;
}

aside > div {
  margin-bottom: 30px;
}

aside > div:last-child {
  margin-bottom: 0;
}

aside > div:last-child > div {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 15px;
}

aside > div:last-child > div > div {
  background: var(--bg-card);
  border-radius: 10px;
  padding: 15px;
  text-align: center;
  transition: var(--transition);
}

aside > div:last-child > div > div:hover {
  background: var(--bg-card-hover);
  transform: scale(1.03);
}

aside > div:last-child p:first-child {
  color: var(--text-secondary);
  margin: 0;
  font-size: 0.85em;
}

aside > div:last-child p:last-child {
  color: var(--accent-light);
  margin: 5px 0 0 0;
  font-size: 1.5em;
  font-weight: bold;
}

/* ---------- 页脚 ---------- */
footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  padding: 40px 5% 20px 5%;
  margin-top: 50px;
}

footer > div {
  max-width: 1400px;
  margin: 0 auto;
}

footer > div > div:first-child {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 30px;
  margin-bottom: 30px;
}

footer h3 {
  color: var(--text-primary);
  font-size: 1.2em;
  margin-bottom: 15px;
}

footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

footer ul li {
  margin-bottom: 8px;
}

footer ul li a {
  color: var(--accent-light);
  text-decoration: none;
  font-size: 0.9em;
  transition: var(--transition);
  position: relative;
  padding-left: 0;
}

footer ul li a:hover {
  color: var(--text-primary);
  padding-left: 10px;
}

footer p {
  color: var(--text-muted);
  font-size: 0.85em;
  margin: 5px 0;
}

footer > div > div:last-child {
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
  text-align: center;
}

footer > div > div:last-child p {
  font-size: 0.8em;
}

/* ---------- 滚动动画 ---------- */
@media (prefers-reduced-motion: no-preference) {
  section {
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
  }
  
  section:nth-of-type(2) {
    animation-delay: 0.1s;
  }
  
  section:nth-of-type(3) {
    animation-delay: 0.2s;
  }
  
  section:nth-of-type(4) {
    animation-delay: 0.3s;
  }
  
  section:nth-of-type(5) {
    animation-delay: 0.4s;
  }
  
  section:nth-of-type(6) {
    animation-delay: 0.5s;
  }
}

/* ---------- 响应式设计 ---------- */
@media screen and (max-width: 1200px) {
  main > div {
    grid-template-columns: 1fr;
  }
  
  aside {
    position: static;
    top: auto;
    margin-top: 30px;
  }
  
  aside > div:last-child > div {
    grid-template-columns: repeat(4, 1fr);
  }
}

@media screen and (max-width: 768px) {
  header {
    padding: 0 3%;
  }
  
  header nav {
    flex-direction: column;
    gap: 15px;
    padding: 15px 0;
  }
  
  header h1 {
    font-size: 1.5em;
  }
  
  header nav > div {
    gap: 15px;
    justify-content: center;
  }
  
  header nav a {
    font-size: 13px;
  }
  
  main {
    padding: 20px 3%;
  }
  
  section h2 {
    font-size: 1.5em;
  }
  
  #hot > div {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 15px;
  }
  
  #recommend > div {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  #detail,
  #platform {
    padding: 20px;
  }
  
  #app {
    padding: 30px 20px;
  }
  
  #app a {
    padding: 12px 30px;
    font-size: 1em;
  }
  
  #characters > div {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 15px;
  }
  
  #reviews > div {
    grid-template-columns: 1fr;
  }
  
  aside > div:last-child > div {
    grid-template-columns: repeat(2, 1fr);
  }
  
  footer {
    padding: 30px 3% 15px 3%;
  }
}

@media screen and (max-width: 480px) {
  header h1 {
    font-size: 1.3em;
  }
  
  header nav a {
    font-size: 12px;
  }
  
  #hot > div {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }
  
  #hot article > div {
    padding: 10px;
  }
  
  #hot article h3 {
    font-size: 0.95em;
  }
  
  #hot article p {
    font-size: 0.8em;
  }
  
  #characters > div {
    grid-template-columns: 1fr;
  }
  
  #characters article img {
    width: 120px !important;
    height: 120px !important;
  }
  
  #app > div {
    flex-direction: column;
    align-items: center;
  }
  
  #app a {
    width: 100%;
    max-width: 280px;
    text-align: center;
  }
  
  aside > div:last-child > div {
    grid-template-columns: 1fr 1fr;
  }
  
  footer > div > div:first-child {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

/* ---------- 暗色模式支持 ---------- */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #0a0a18;
    --bg-secondary: #14142e;
    --bg-card: #1a1a35;
    --bg-card-hover: #1f1f42;
    --border-color: #2d2d55;
    --text-primary: #f0f0ff;
    --text-secondary: #d0d0e8;
    --text-muted: #8888aa;
  }
}

/* ---------- 毛玻璃效果增强 ---------- */
.glass-effect {
  background: rgba(20, 20, 46, 0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(139, 92, 246, 0.15);
}

/* ---------- 卡片悬浮特效 ---------- */
.card-hover-effect {
  position: relative;
  overflow: hidden;
}

.card-hover-effect::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.05), transparent);
  transition: var(--transition);
}

.card-hover-effect:hover::after {
  left: 100%;
}

/* ---------- 图片加载动画 ---------- */
img {
  background: linear-gradient(90deg, var(--bg-card) 25%, var(--bg-card-hover) 50%, var(--bg-card) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

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

/* ---------- 标题渐变动画 ---------- */
.gradient-text {
  background: linear-gradient(90deg, #7c3aed, #a78bfa, #7c3aed);
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 3s linear infinite;
}

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

/* ---------- 滚动进度条 ---------- */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--accent-gradient);
  z-index: 9999;
  transition: width 0.3s ease;
}

/* ---------- 回到顶部按钮 ---------- */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--accent-gradient);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: var(--transition);
  opacity: 0;
  visibility: hidden;
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

/* ---------- 打印样式 ---------- */
@media print {
  header,
  aside,
  footer,
  #app,
  .back-to-top {
    display: none !important;
  }
  
  body {
    background: white;
    color: black;
  }
  
  main {
    max-width: 100%;
    padding: 0;
  }
  
  section {
    opacity: 1 !important;
    animation: none !important;
  }
}
```