/* 
===============================
收藏鸭官网 - 主样式文件
参考胃之书设计风格，融入收藏鸭特色
===============================
*/

/* CSS Variables */
:root {
  /* 品牌色彩 */
  --primary-color: #007AFF;
  --primary-gradient: linear-gradient(135deg, #007AFF 0%, #5856D6 100%);
  --secondary-color: #5856D6;
  --accent-color: #FF9500;
  
  /* 中性色彩 */
  --text-primary: #1D1D1F;
  --text-secondary: #6E6E73;
  --text-tertiary: #98989D;
  --background-primary: #FFFFFF;
  --background-secondary: #F5F5F7;
  --background-tertiary: #FAFAFA;
  
  /* 功能色彩 */
  --success-color: #30D158;
  --warning-color: #FF9F0A;
  --error-color: #FF3B30;
  
  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.1);
  
  /* 圆角 */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  
  /* 间距 */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;
  --spacing-4xl: 96px;
  
  /* 字体 */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --font-size-2xl: 24px;
  --font-size-3xl: 30px;
  --font-size-4xl: 36px;
  --font-size-5xl: 48px;
  --font-size-6xl: 60px;
  
  /* 动画 */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* 暗色模式 */
@media (prefers-color-scheme: dark) {
  :root {
    --text-primary: #F5F5F7;
    --text-secondary: #A1A1A6;
    --text-tertiary: #8E8E93;
    --background-primary: #000000;
    --background-secondary: #1C1C1E;
    --background-tertiary: #2C2C2E;
  }
  
  .hero-buttons .btn-secondary {
    background: #2C2C2E;
    color: var(--text-primary);
    border-color: #48484A;
  }
  
  .hero-buttons .btn-secondary:hover {
    background: #3A3A3C;
    border-color: #6D6D70;
  }
}

/* 基础重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--background-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-md);
  }
}

/* 通用组件 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md) var(--spacing-xl);
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-normal);
  white-space: nowrap;
}

.btn-primary {
  background: var(--primary-gradient);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--background-secondary);
  color: var(--text-primary);
  border: 1px solid var(--text-tertiary);
}

.btn-secondary:hover {
  background: var(--background-tertiary);
  border-color: var(--text-secondary);
}

/* 渐变文字 */
.gradient-text {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* 章节标题 */
.section-title {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  text-align: center;
}

.section-subtitle {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--spacing-3xl);
}

.section-header {
  margin-bottom: var(--spacing-4xl);
}

/* 导航栏 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
  z-index: 1000;
  transition: all var(--transition-normal);
}

/* 语言切换器 */
.language-switcher {
  position: relative;
  display: inline-flex;
  align-items: center;
}

.language-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: white;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 14px;
}

.language-toggle:hover {
  background: #f5f5f5;
  border-color: #4a90e2;
}

.current-lang-flag {
  font-size: 16px;
}

.current-lang-name {
  font-weight: 500;
  color: var(--text-primary);
}

.dropdown-icon {
  transition: transform var(--transition-base);
}

.language-dropdown.show .dropdown-icon {
  transform: rotate(180deg);
}

.language-dropdown {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: 4px;
  background: white;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all 0.2s ease;
  min-width: 150px;
  z-index: 1001;
  pointer-events: none;
}

.language-dropdown.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.language-option {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 8px 12px;
  background: none;
  border: none;
  cursor: pointer;
  transition: background-color 0.2s ease;
  font-size: 14px;
}

.language-option:hover {
  background: #f5f5f5;
}

.language-option.active {
  background: #4a90e2;
  color: white;
}

.language-option.active .lang-name {
  color: white;
}

.lang-flag {
  font-size: 16px;
}

.lang-name {
  font-weight: 500;
  color: var(--text-primary);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-md) var(--spacing-lg);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
}

.logo-image {
  width: 32px;
  height: 32px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: var(--primary-color);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  cursor: pointer;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: all var(--transition-fast);
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 76px;
    left: 0;
    width: 100%;
    background: var(--background-primary);
    box-shadow: var(--shadow-lg);
    flex-direction: column;
    padding: var(--spacing-lg);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 999;
  }
  
  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav-menu .language-switcher {
    margin-top: var(--spacing-md);
    justify-content: center;
  }
  
  .nav-link {
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--background-secondary);
    font-size: var(--font-size-lg);
  }
  
  .nav-link:last-child {
    border-bottom: none;
  }
  
  .nav-toggle {
    display: flex;
  }
  
  .nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  
  .nav-toggle.active span:nth-child(2) {
    opacity: 0;
  }
  
  .nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
  }
  
  body.menu-open {
    overflow: hidden;
  }
}

/* 英雄区域 */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 80px;
  overflow: hidden;
  background: linear-gradient(135deg, 
    var(--background-primary) 0%, 
    rgba(74, 144, 226, 0.03) 30%, 
    rgba(80, 200, 120, 0.03) 70%, 
    var(--background-primary) 100%);
}

/* 英雄区域装饰元素 */
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 30%, rgba(74, 144, 226, 0.05) 0%, transparent 50%),
              radial-gradient(circle at 70% 70%, rgba(80, 200, 120, 0.05) 0%, transparent 50%);
  animation: heroFloating 20s ease-in-out infinite;
  z-index: 0;
}

.hero::after {
  content: '';
  position: absolute;
  top: 10%;
  right: 10%;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(74, 144, 226, 0.08) 0%, transparent 70%);
  border-radius: 50%;
  animation: heroFloating 15s ease-in-out infinite reverse;
  z-index: 0;
}

.hero-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-4xl);
  align-items: center;
  max-width: 1200px;
  position: relative;
  z-index: 1;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.hero-content {
  z-index: 2;
}

.hero-title {
  font-size: var(--font-size-6xl);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--spacing-lg);
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-2xl);
  line-height: 1.5;
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-3xl);
  align-items: center;
  animation: fadeInUp 0.8s ease-out 0.6s both;
  position: relative;
  z-index: 10;
}

.hero-buttons .btn-primary {
  background: none;
  border: none;
  padding: 0;
  position: relative;
  z-index: 10;
  pointer-events: auto;
  cursor: pointer;
}

.hero-buttons img {
  height: 48px;
}

.hero-buttons .btn-secondary {
  height: 48px;
  min-width: 160px;
  padding: 12px 24px;
  background: #F5F5F7;
  color: var(--text-primary);
  border: 1px solid #D1D1D6;
  border-radius: 24px;
  font-size: var(--font-size-base);
  font-weight: 500;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-normal);
  position: relative;
  z-index: 10;
  pointer-events: auto;
  cursor: pointer;
}

.hero-buttons .btn-secondary:hover {
  background: #E5E5E7;
  border-color: #B0B0B5;
  transform: scale(1.05);
}

.hero-stats {
  display: flex;
  gap: var(--spacing-2xl);
}

.stat-item {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--primary-color);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.hero-visual {
  position: relative;
  z-index: 2;
}

.phone-mockup {
  position: relative;
  max-width: 450px;
  margin: 0 auto;
  animation: scaleIn 1s ease-out 0.8s both;
}

/* 大屏幕上进一步放大 */
@media (min-width: 1200px) {
  .phone-mockup {
    max-width: 500px;
  }
}

.hero-image {
  width: 100%;
  height: auto;
  filter: drop-shadow(var(--shadow-xl));
}





@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-20px); }
}

@keyframes heroFloating {
  0%, 100% { 
    transform: translate(0, 0) rotate(0deg); 
  }
  25% { 
    transform: translate(10px, -15px) rotate(1deg); 
  }
  50% { 
    transform: translate(-5px, -10px) rotate(-0.5deg); 
  }
  75% { 
    transform: translate(-15px, 5px) rotate(0.8deg); 
  }
}

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

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.8);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}





.hero-bg-elements {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 0;
}

.bg-circle {
  position: absolute;
  border-radius: 50%;
  background: var(--primary-gradient);
  opacity: 0.1;
  animation: pulse 4s ease-in-out infinite;
}

.circle-1 {
  width: 200px;
  height: 200px;
  top: 10%;
  left: 10%;
}

.circle-2 {
  width: 300px;
  height: 300px;
  top: 60%;
  right: 10%;
  animation-delay: 2s;
}

.circle-3 {
  width: 150px;
  height: 150px;
  bottom: 10%;
  left: 30%;
  animation-delay: 1s;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.1; }
  50% { transform: scale(1.1); opacity: 0.2; }
}

@media (max-width: 768px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--spacing-2xl);
  }
  
  .hero-title {
    font-size: var(--font-size-4xl);
  }
  
  .hero-subtitle {
    font-size: var(--font-size-lg);
  }
  
  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .hero-stats {
    justify-content: center;
  }
  
  .phone-mockup {
    max-width: 320px;
  }

}

/* 功能特色区域 */
.features {
  padding: var(--spacing-4xl) 0;
  background: var(--background-secondary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--spacing-xl);
}

.feature-card {
  position: relative;
  background: var(--background-primary);
  border-radius: var(--radius-lg);
  padding: var(--spacing-2xl);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
}

.feature-card.featured {
  border: 2px solid var(--primary-color);
}

.feature-badge {
  position: absolute;
  top: -10px;
  right: var(--spacing-lg);
  background: var(--primary-gradient);
  color: white;
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  font-weight: 600;
}

.feature-icon {
  width: 60px;
  height: 60px;
  margin-bottom: var(--spacing-lg);
}

.feature-icon img {
  width: 100%;
  height: 100%;
}

.feature-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.feature-description {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.6;
}

.feature-list {
  list-style: none;
}

.feature-list li {
  position: relative;
  padding-left: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
  color: var(--text-secondary);
}

.feature-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--success-color);
  font-weight: 600;
}

@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
}

/* 截图展示区域 */
.screenshots {
  padding: var(--spacing-4xl) 0;
}

.screenshots-slider {
  display: flex;
  gap: var(--spacing-xl);
  overflow-x: auto;
  padding: var(--spacing-lg) 0;
  scroll-snap-type: x mandatory;
}

.screenshot-item {
  flex: 0 0 250px;
  text-align: center;
  scroll-snap-align: start;
}

.screenshot-item img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  margin-bottom: var(--spacing-md);
}

.screenshot-item h4 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.screenshot-item p {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

/* 关于我们区域 */
.about {
  padding: var(--spacing-4xl) 0;
  background: var(--background-secondary);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-4xl);
  align-items: center;
}

.about-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: var(--spacing-2xl);
}

.about-features {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.about-feature h4 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.about-feature p {
  color: var(--text-secondary);
  line-height: 1.6;
}

.about-visual {
  text-align: center;
}

.about-image img {
  width: 100%;
  max-width: 400px;
  height: auto;
}

@media (max-width: 768px) {
  .about-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
  }
  
  .about-text {
    order: 2;
  }
  
  .about-visual {
    order: 1;
  }
}

/* 下载区域 */
.download {
  padding: var(--spacing-4xl) 0;
  text-align: center;
}

.download-content {
  max-width: 800px;
  margin: 0 auto;
}

.download-buttons {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: var(--spacing-3xl);
}

.download-btn {
  background: none;
  border: none;
  padding: 0;
}

.download-btn img {
  height: 60px;
  transition: transform var(--transition-normal);
}

.download-btn:hover img {
  transform: scale(1.05);
}

.download-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--spacing-lg);
  max-width: 600px;
  margin: 0 auto;
}

.info-item {
  text-align: center;
  padding: var(--spacing-lg);
  background: var(--background-secondary);
  border-radius: var(--radius-md);
}

.info-label {
  display: block;
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.info-value {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
}

@media (max-width: 768px) {
  .download-info {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* 联系我们区域 */
.contact {
  padding: var(--spacing-4xl) 0;
  background: var(--background-secondary);
}

.contact-content {
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
}

.contact-simple {
  margin-top: var(--spacing-2xl);
}

.contact-email {
  font-size: var(--font-size-xl);
  color: var(--text-secondary);
  font-weight: 500;
}

/* 页脚 */
.footer {
  background: var(--text-primary);
  color: var(--background-primary);
  padding: var(--spacing-4xl) 0 var(--spacing-lg);
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--spacing-4xl);
  margin-bottom: var(--spacing-2xl);
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.footer-tagline {
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: var(--spacing-lg);
}

.social-links {
  display: flex;
  gap: var(--spacing-md);
}

.social-link {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  transition: all var(--transition-fast);
}

.social-link:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.social-link img {
  width: 20px;
  height: 20px;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-2xl);
}

.link-group h4 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.link-group ul {
  list-style: none;
}

.link-group li {
  margin-bottom: var(--spacing-sm);
}

.link-group a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.link-group a:hover {
  color: white;
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.5);
  font-size: var(--font-size-sm);
}

.footer-bottom p:first-child {
  margin-bottom: var(--spacing-xs);
}

@media (max-width: 768px) {
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
  }
  
  .footer-links {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
}

/* 动画和效果 */
@media (prefers-reduced-motion: no-preference) {
  .feature-card,
  .screenshot-item,
  .btn {
    transition: transform var(--transition-normal);
  }
  
  .feature-card:hover {
    transform: translateY(-4px);
  }
  
  .screenshot-item:hover {
    transform: scale(1.05);
  }
}

/* 隐藏滚动条但保留滚动功能 */
.screenshots-slider::-webkit-scrollbar {
  display: none;
}

.screenshots-slider {
  -ms-overflow-style: none;  /* Internet Explorer 10+ */
  scrollbar-width: none;  /* Firefox */
}

/* 加载动画 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.6s ease forwards;
}

/* 实用类 */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

/* 响应式图片 */
img {
  max-width: 100%;
  height: auto;
}

/* 可访问性 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* 焦点样式 */
:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* 选择文本样式 */
::selection {
  background: var(--primary-color);
  color: white;
}