/* 全局 CSS 变量 */
:root {
  /* 主色调 - 科技蓝 */
  --primary-color: #1a73e8;
  --primary-color-light: #4285f4;
  --primary-color-dark: #1557b0;
  
  /* 辅助色 - 科技青 */
  --secondary-color: #00bcd4;
  --secondary-color-light: #26c6da;
  --secondary-color-dark: #0097a7;
  
  /* 深色主题 */
  --dark-color: #1a202c;
  --dark-color-light: #2d3748;
  --dark-color-dark: #171923;
  
  /* 中性色 */
  --gray-color: #4a5568;
  --gray-color-light: #718096;
  --gray-color-dark: #2d3748;
  --border-color: #e2e8f0;
  --background-color: #f7fafc;
  
  /* 状态色 */
  --success-color: #34a853;
  --warning-color: #fbbc05;
  --error-color: #ea4335;
  --info-color: #1a73e8;
  
  /* 字体 */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  
  /* 间距 */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* 圆角 */
  --border-radius-sm: 0.25rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  --border-radius-full: 9999px;
  
  /* 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 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
  
  /* 过渡 */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* 全局样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

/* 标题样式 */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--dark-color);
}

h1 {
  font-size: var(--font-size-4xl);
  @media (min-width: 768px) {
    font-size: var(--font-size-5xl);
  }
}

h2 {
  font-size: var(--font-size-3xl);
  @media (min-width: 768px) {
    font-size: var(--font-size-4xl);
  }
}

h3 {
  font-size: var(--font-size-2xl);
  @media (min-width: 768px) {
    font-size: var(--font-size-3xl);
  }
}

h4 {
  font-size: var(--font-size-xl);
}

/* 链接样式 */
a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color var(--transition-normal);
}

a:hover {
  color: var(--primary-color-dark);
}

/* 按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: var(--font-size-base);
  line-height: 1.5;
  padding: 0.625rem 1.5rem;
  border-radius: var(--border-radius-full);
  transition: all var(--transition-normal);
  cursor: pointer;
  border: none;
  outline: none;
  font-family: var(--font-family);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-color-dark), var(--secondary-color-dark));
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
  background-color: var(--secondary-color-dark);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.btn-outline {
  background-color: transparent;
  color: var(--primary-color);
  border: 2px solid var(--primary-color);
}

.btn-outline:hover {
  background-color: var(--primary-color);
  color: white;
}

/* 表单样式 */
.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: var(--font-size-base);
  font-family: var(--font-family);
  line-height: 1.5;
  color: var(--dark-color);
  background-color: white;
  background-clip: padding-box;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.1);
}

.form-control::placeholder {
  color: var(--gray-color-light);
}

/* 导航栏样式 */
.navbar {
  background-color: white;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
  padding: 0.5rem 0;
}

.nav-link {
  font-weight: 500;
  color: var(--dark-color);
  transition: all var(--transition-normal);
  position: relative;
  padding: 0.5rem 0;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  transition: width var(--transition-normal);
}

.nav-link:hover::after {
  width: 100%;
}

/* 下拉菜单样式 */
.dropdown {
  position: relative;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  right: 0;
  z-index: 1000;
  display: none;
  min-width: 12rem;
  padding: 0.5rem 0;
  margin: 0.125rem 0 0;
  font-size: var(--font-size-base);
  color: var(--dark-color);
  text-align: left;
  background-color: white;
  background-clip: padding-box;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transform: translateY(-10px);
  transition: all var(--transition-normal);
}

.dropdown:hover .dropdown-menu {
  display: block;
  opacity: 1;
  transform: translateY(0);
}

.dropdown-item {
  display: block;
  width: 100%;
  padding: 0.5rem 1rem;
  clear: both;
  font-weight: 400;
  color: var(--dark-color);
  text-align: inherit;
  text-decoration: none;
  white-space: nowrap;
  background-color: transparent;
  border: 0;
  transition: all var(--transition-normal);
  border-radius: var(--border-radius-md);
  margin: 0 0.25rem;
}

.dropdown-item:hover {
  background-color: var(--primary-color);
  color: white;
}

.dropdown-toggle::after {
  content: '';
  margin-left: 0.255em;
  vertical-align: 0.255em;
  border-top: 0.3em solid;
  border-right: 0.3em solid transparent;
  border-bottom: 0;
  border-left: 0.3em solid transparent;
}

/* 移动端菜单样式 */
.mobile-menu-btn {
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: var(--border-radius-md);
  transition: all var(--transition-normal);
}

.mobile-menu-btn:hover {
  background-color: var(--background-color);
}

.mobile-menu {
  position: fixed;
  top: 0;
  right: -100%;
  width: 80%;
  max-width: 300px;
  height: 100vh;
  background-color: white;
  box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
  z-index: 1001;
  transition: right var(--transition-normal);
  overflow-y: auto;
}

.mobile-menu.open {
  right: 0;
}

.menu-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  display: none;
  transition: opacity var(--transition-normal);
}

.menu-overlay.open {
  display: block;
}

.mobile-dropdown-btn {
  background: none;
  border: none;
  width: 100%;
  text-align: left;
  cursor: pointer;
  padding: 0.5rem 0;
  font-weight: 500;
  color: var(--dark-color);
  transition: all var(--transition-normal);
}

.mobile-dropdown-btn:hover {
  color: var(--primary-color);
}

.mobile-dropdown {
  transition: all var(--transition-normal);
  overflow: hidden;
}

/* 搜索框样式 */
.search-container {
  position: relative;
  width: 250px;
}

.search-input {
  width: 100%;
  padding: 0.5rem 2.5rem 0.5rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-full);
  font-size: var(--font-size-sm);
  transition: all var(--transition-normal);
  background-color: var(--background-color);
}

.search-input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.1);
  background-color: white;
}

.search-results {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  background-color: white;
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  max-height: 300px;
  overflow-y: auto;
}

/* 页脚样式 */
.footer {
  background: linear-gradient(135deg, var(--dark-color-dark), var(--dark-color));
  color: white;
}

.footer-link {
  color: rgba(255, 255, 255, 0.7);
  transition: all var(--transition-normal);
  display: block;
  padding: 0.25rem 0;
}

.footer-link:hover {
  color: white;
  transform: translateX(5px);
}

.social-links {
  display: flex;
  gap: 1rem;
}

.social-links a {
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--border-radius-full);
  background-color: rgba(255, 255, 255, 0.1);
  color: white;
  transition: all var(--transition-normal);
}

.social-links a:hover {
  background-color: var(--primary-color);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

/* 卡片样式 */
.card {
  background-color: white;
  border-radius: var(--border-radius-xl);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-5px);
}

.product-card {
  background-color: white;
  border-radius: var(--border-radius-xl);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.product-card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-5px);
}

.product-info {
  padding: 1.5rem;
}

.product-price {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--primary-color);
}

.product-old-price {
  font-size: var(--font-size-base);
  color: var(--gray-color-light);
  text-decoration: line-through;
  margin-left: 0.5rem;
}

.discount-badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background-color: var(--error-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: var(--border-radius-full);
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.stars {
  color: var(--warning-color);
  font-size: var(--font-size-sm);
}

/* 文章卡片样式 */
.article-card {
  background-color: white;
  border-radius: var(--border-radius-xl);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.article-card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-5px);
}

.article-info {
  padding: 1.5rem;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: var(--font-size-sm);
  color: var(--gray-color-light);
  margin-bottom: 1rem;
}

/* 标签云样式 */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag-cloud a {
  display: inline-block;
  padding: 0.375rem 0.875rem;
  background-color: var(--background-color);
  color: var(--dark-color);
  border-radius: var(--border-radius-full);
  font-size: var(--font-size-sm);
  font-weight: 500;
  transition: all var(--transition-normal);
}

.tag-cloud a:hover {
  background-color: var(--primary-color);
  color: white;
  transform: translateY(-2px);
}

/* 回到顶部按钮 */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 3rem;
  height: 3rem;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  border: none;
  border-radius: var(--border-radius-full);
  box-shadow: var(--shadow-lg);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  z-index: 999;
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-3px);
}

/* 滚动动画 */
.scroll-animate {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease;
}

.scroll-animate.animated {
  opacity: 1;
  transform: translateY(0);
}

/* 渐变背景 */
.gradient-bg {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

/* 科技网格背景 */
.tech-grid {
  background-image: 
    linear-gradient(rgba(26, 115, 232, 0.1) 1px, transparent 1px),
    linear-gradient(90deg, rgba(26, 115, 232, 0.1) 1px, transparent 1px);
  background-size: 20px 20px;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .search-container {
    width: 100%;
  }
  
  .mobile-menu {
    width: 90%;
  }
  
  h1 {
    font-size: var(--font-size-3xl);
  }
  
  h2 {
    font-size: var(--font-size-2xl);
  }
  
  h3 {
    font-size: var(--font-size-xl);
  }
}

/* 加载动画 */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* 标签页样式 */
.tab-navigation {
  display: flex;
  flex-wrap: wrap;
  border-bottom: 1px solid var(--border-color);
}

.tab-btn {
  padding: 1rem 2rem;
  background: none;
  border: none;
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--gray-color-light);
  cursor: pointer;
  transition: all var(--transition-normal);
  border-bottom: 2px solid transparent;
}

.tab-btn:hover {
  color: var(--primary-color);
}

.tab-btn.active {
  color: var(--primary-color);
  border-bottom-color: var(--primary-color);
}

.tab-content {
  padding: 2rem 0;
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: block;
}

/* 计数器动画 */
.counter {
  font-weight: 700;
  color: var(--primary-color);
}

/* 悬停效果 */
.hover-lift {
  transition: transform var(--transition-normal);
}

.hover-lift:hover {
  transform: translateY(-5px);
}

.hover-scale {
  transition: transform var(--transition-normal);
}

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

/* 卡片阴影变化 */
.hover-shadow {
  transition: box-shadow var(--transition-normal);
}

.hover-shadow:hover {
  box-shadow: var(--shadow-xl);
}

/* 文本渐变 */
.text-gradient {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* 分隔线 */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-color), transparent);
  margin: 2rem 0;
}

/* 响应式容器 */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* 动画延迟 */
.delay-100 {
  transition-delay: 0.1s;
}

.delay-200 {
  transition-delay: 0.2s;
}

.delay-300 {
  transition-delay: 0.3s;
}

.delay-400 {
  transition-delay: 0.4s;
}

.delay-500 {
  transition-delay: 0.5s;
}

/* 图片懒加载 */
.lazy-load {
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.lazy-load.loaded {
  opacity: 1;
}

/* 骨架屏 */
.skeleton {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
}

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

/* 通知样式 */
.notification {
  position: fixed;
  top: 2rem;
  right: 2rem;
  padding: 1rem 1.5rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-xl);
  z-index: 1001;
  animation: slide-in 0.3s ease-out;
}

@keyframes slide-in {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

/* 模态框样式 */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1002;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.modal.open {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background-color: white;
  border-radius: var(--border-radius-xl);
  box-shadow: var(--shadow-xl);
  padding: 2rem;
  max-width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  transform: scale(0.9);
  transition: transform var(--transition-normal);
}

.modal.open .modal-content {
  transform: scale(1);
}

/* 滑块样式 */
input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 8px;
  border-radius: 4px;
  background: var(--border-color);
  outline: none;
  transition: background var(--transition-normal);
}

input[type="range"]:hover {
  background: var(--gray-color-light);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  cursor: pointer;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: var(--shadow-lg);
}

input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  cursor: pointer;
  border: none;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

input[type="range"]::-moz-range-thumb:hover {
  transform: scale(1.2);
  box-shadow: var(--shadow-lg);
}