/* 渐进式交互主题 - 极光蓝 */
:root {
    --primary-color: #4d8af0; /* 极光蓝 */
    --primary-light: #78a9ff;
    --primary-dark: #1a56b4;
    --secondary-color: #00c1b3; /* 辅助色 - 青绿色 */
    --dark-color: #1a1e26;
    --darker-color: #12161e;
    --light-color: #f8f9fa;
    --text-color: #e0e6f0;
    --text-muted: #a0a8b8;
    --transition-speed: 0.4s;
    --border-radius: 12px;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.2);
  }
  
  /* 基础样式 - 渐进增强 */
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  html {
    scroll-behavior: smooth;
  }
  
  body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--darker-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color var(--transition-speed);
  }
  
  /* 渐进式加载动画 */
  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
  }
  
  .progressive-load {
    animation: fadeIn 0.6s ease-out forwards;
  }
  
  /* 布局容器 */
  .container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }
  
  /* 渐进式头部 - 滚动时变化 */
  header {
    background-color: rgba(26, 30, 38, 0.9);
    backdrop-filter: blur(10px);
    padding: 18px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-speed);
  }
  
  .header-scrolled {
    padding: 12px 0;
    background-color: rgba(18, 22, 30, 0.98);
  }
  
  .header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
  
  .logo {
    font-size: 24px;
    font-weight: 700;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
  }
  
  /* 渐进式导航 */
  .nav-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 24px;
    cursor: pointer;
  }
  
  nav ul {
    display: flex;
    list-style: none;
    gap: 20px;
  }
  
  nav ul li a {
    padding: 8px 16px;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: all var(--transition-speed);
    position: relative;
  }
  
  nav ul li a::after {
    content: '';
    
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: all var(--transition-speed);
    transform: translateX(-50%);
  }
  
  nav ul li a:hover::after {
    width: 60%;
  }
  
  /* 主内容区 - 渐进式卡片 */
  .main-content {
    background-color: var(--dark-color);
    border-radius: var(--border-radius);
    padding: 30px;
    margin: 30px 0;
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
  }
  
  .main-content:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
  }
  
  .section-title {
    font-size: 24px;
    margin-bottom: 25px;
    position: relative;
    display: inline-block;
  }
  
  .section-title::after {
    content: '';
    
    bottom: -8px;
    left: 0;
    width: 40px;
    height: 3px;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    border-radius: 3px;
  }
  
  /* 渐进式网格布局 */
  .article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeIn 0.8s ease-out 0.2s forwards;
  }
  
  .article-card {
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: all var(--transition-speed);
    border: 1px solid rgba(255, 255, 255, 0.05);
    position: relative;
  }
  
  .article-card::before {
    content: '';
    
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(77, 138, 240, 0.1), rgba(0, 193, 179, 0.1));
    opacity: 0;
    transition: opacity var(--transition-speed);
  }
  
  .article-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(77, 138, 240, 0.3);
  }
  
  .article-card:hover::before {
    opacity: 1;
  }
  
  .card-image {
    width: 100%;
    height: 180px;
    object-fit: cover;
    transition: transform var(--transition-speed);
  }
  
  .article-card:hover .card-image {
    transform: scale(1.03);
  }
  
  .card-body {
    padding: 20px;
  }
  
  .card-title {
    font-size: 18px;
    margin-bottom: 12px;
    font-weight: 600;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }
  
  .card-meta {
    display: flex;
    justify-content: space-between;
    font-size: 14px;
    color: var(--text-muted);
    margin-top: 15px;
  }
  
  /* 渐进式分类标签 */
  .category-tag {
    display: inline-block;
    padding: 4px 12px;
    background-color: rgba(77, 138, 240, 0.2);
    color: var(--primary-light);
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
    margin-bottom: 12px;
    transition: all var(--transition-speed);
  }
  
  .category-tag:hover {
    background-color: var(--primary-color);
    color: white;
  }
  
  /* 渐进式文章详情 */
  .article-detail {
    max-width: 800px;
    margin: 0 auto;
    opacity: 0;
    animation: fadeIn 0.8s ease-out forwards;
  }
  
  .article-header {
    margin-bottom: 40px;
    text-align: center;
  }
  
  .article-title {
    font-size: 32px;
    margin-bottom: 20px;
    line-height: 1.3;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
  }
  
  .article-meta {
    display: flex;
    justify-content: center;
    gap: 20px;
    color: var(--text-muted);
    margin-bottom: 25px;
    flex-wrap: wrap;
  }
  
  .article-image {
    width: 100%;
    max-height: 450px;
    object-fit: cover;
    border-radius: var(--border-radius);
    margin-bottom: 30px;
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-speed);
  }
  
  .article-image:hover {
    transform: scale(1.02);
  }
  
  .article-content {
    line-height: 1.8;
    font-size: 17px;
  }
  
  .article-content p {
    margin-bottom: 20px;
  }
  
  .article-content img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 20px 0;
    box-shadow: var(--shadow-sm);
  }
  
  /* 渐进式分页 */
  .pagination {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 40px;
  }
  
  .pagination a {
    padding: 10px 20px;
    border-radius: var(--border-radius);
    background-color: rgba(77, 138, 240, 0.1);
    border: 1px solid var(--primary-color);
    transition: all var(--transition-speed);
    font-weight: 500;
  }
  
  .pagination a:hover {
    background-color: var(--primary-color);
    color: white;
  }
  
  /* 渐进式友情链接 */
  .friend-links {
    background-color: rgba(255, 255, 255, 0.03);
    border-radius: var(--border-radius);
    padding: 25px;
    margin: 30px 0;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: all var(--transition-speed);
  }
  
  .friend-links:hover {
    background-color: rgba(255, 255, 255, 0.06);
    border-color: rgba(77, 138, 240, 0.2);
  }
  
  .friend-links h3 {
    margin-bottom: 20px;
    font-size: 20px;
  }
  
  .friend-links-container {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
  }
  
  .friend-links-container a {
    padding: 8px 16px;
    background-color: rgba(77, 138, 240, 0.1);
    border-radius: var(--border-radius);
    font-size: 14px;
    border: 1px solid var(--primary-color);
    transition: all var(--transition-speed);
  }
  
  .friend-links-container a:hover {
    background-color: var(--primary-color);
    color: white;
  }
  
  /* 渐进式页脚 */
  footer {
    background-color: rgba(18, 22, 30, 0.98);
    padding: 30px 0;
    text-align: center;
    margin-top: auto;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
  }
  
  .copyright {
    font-size: 14px;
    color: var(--text-muted);
  }
  
  /* 渐进式响应式设计 */
  @media (max-width: 992px) {
    .article-grid {
      grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    }
  }
  
  @media (max-width: 768px) {
    .header-content {
      flex-direction: column;
      gap: 20px;
    }
    
    .nav-toggle {
      display: block;
    }
    
    nav {
      width: 100%;
      max-height: 0;
      overflow: hidden;
      transition: max-height var(--transition-speed);
    }
    
    nav.active {
      max-height: 500px;
    }
    
    nav ul {
      flex-direction: column;
      gap: 10px;
      padding-top: 20px;
    }
    
    .article-title {
      font-size: 26px;
    }
    
    .article-meta {
      gap: 15px;
    }
  }
  
  @media (max-width: 576px) {
    .main-content {
      padding: 20px;
    }
    
    .article-grid {
      grid-template-columns: 1fr;
    }
    
    .pagination {
      flex-direction: column;
      align-items: center;
    }
  }
  
  /* 渐进式交互增强 */
  @media (prefers-reduced-motion: reduce) {
    html {
      scroll-behavior: auto;
    }
    
    .progressive-load, 
    .article-detail,
    .article-grid {
      animation: none;
      opacity: 1;
      transform: none;
    }
  }
  
  /* 暗黑模式增强 */
  @media (prefers-color-scheme: dark) {
    body {
      background-color: #121212;
    }
    
    header, footer {
      background-color: rgba(0, 0, 0, 0.9);
    }
  }