/* 全局样式 */
  :root {
    --primary: #2C3E50;
    --secondary: #3498DB;
    --accent: #2ECC71;
    --text: #ECF0F1;
    --text-secondary: #BDC3C7;
    --bg: #1A1A1A;
    --card-bg: #333;
  }

  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }

  body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
  }

  body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 20% 30%, rgba(46, 204, 113, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 80% 70%, rgba(52, 152, 219, 0.1) 0%, transparent 50%);
    z-index: -1;
    opacity: 0.5;
  }

  /* 容器样式 */
  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
  }

  /* 标题样式 */
  h1, h2, h3, h4 {
    font-weight: 700;
    margin-bottom: 20px;
    position: relative;
  }

  h1 {
    font-size: 2.5rem;
    background: linear-gradient(90deg, var(--secondary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    padding-bottom: 15px;
  }

  h2 {
    font-size: 2rem;
    color: var(--text);
    margin-top: 40px;
  }

  h2::after {
    content: '';
    display: block;
    width: 100px;
    height: 3px;
    background: linear-gradient(90deg, var(--secondary), var(--accent));
    margin-top: 10px;
  }

  h3 {
    font-size: 1.5rem;
    color: var(--secondary);
    margin-top: 30px;
  }

  /* 段落样式 */
  p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
  }

  /* 卡片样式 */
  .card {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 25px;
    margin-bottom: 30px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
  }

  .card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, var(--secondary), var(--accent));
  }

  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4);
  }

  /* 代码块样式 */
  pre {
    background: #222;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
    overflow: auto;
    position: relative;
    border-left: 4px solid var(--secondary);
  }

  code {
    font-family: 'Courier New', monospace;
    color: #f8f8f2;
    font-size: 0.9rem;
  }

  /* 图片样式 */
  .img-container {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin: 30px 0;
    justify-content: center;
  }

  .img-box {
    width: 320px;
    height: 320px;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    position: relative;
  }

  .img-box:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.4);
  }

  .img-box img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
  }

  .img-box:hover img {
    transform: scale(1.1);
  }

  /* 导航样式 */
  .nav-container {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(26, 26, 26, 0.9);
    backdrop-filter: blur(10px);
    padding: 15px 0;
    border-bottom: 1px solid rgba(52, 152, 219, 0.2);
  }

  .nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }

  .nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 10px;
  }

  .nav-logo::before {
    content: '';
    display: inline-block;
    width: 30px;
    height: 30px;
    background: linear-gradient(45deg, var(--secondary), var(--accent));
    border-radius: 50%;
  }

  .nav-links {
    display: flex;
    gap: 30px;
  }

  .nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
  }

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

  .nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--secondary), var(--accent));
    transition: width 0.3s ease;
  }

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

  /* 页脚样式 */
  footer {
    background: #111;
    padding: 40px 0;
    margin-top: 60px;
    text-align: center;
  }

  .footer-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
  }

  /* 响应式设计 */
  @media (max-width: 768px) {
    .container {
      padding: 15px;
    }

    h1 {
      font-size: 2rem;
    }

    h2 {
      font-size: 1.5rem;
    }

    h3 {
      font-size: 1.2rem;
    }

    .nav-links {
      gap: 15px;
    }

    .img-box {
      width: 280px;
      height: 280px;
    }
  }

  @media (max-width: 480px) {
    .nav {
      flex-direction: column;
      gap: 15px;
    }

    .nav-links {
      flex-wrap: wrap;
      justify-content: center;
    }

    .img-box {
      width: 100%;
      height: auto;
      aspect-ratio: 1/1;
    }
  }

  /* 动画效果 */
  @keyframes float {
    0%, 100% {
      transform: translateY(0);
    }
    50% {
      transform: translateY(-10px);
    }
  }

  .floating {
    animation: float 3s ease-in-out infinite;
  }

  /* 提示样式 */
  .design-note {
    background: rgba(52, 152, 219, 0.1);
    border-left: 4px solid var(--secondary);
    padding: 15px;
    margin: 30px 0;
    border-radius: 0 8px 8px 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
  }

  /* 折叠区域 */
  .collapse {
    margin: 20px 0;
  }

  .collapse-btn {
    background: var(--card-bg);
    color: var(--text);
    border: none;
    padding: 15px;
    width: 100%;
    text-align: left;
    cursor: pointer;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
  }

  .collapse-btn:hover {
    background: #3a3a3a;
  }

  .collapse-btn::after {
    content: '+\\0020';
    font-size: 1.2rem;
  }

  .collapse-btn.active::after {
    content: '-\\0020';
  }

  .collapse-content {
    padding: 0 15px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    background: rgba(51, 51, 51, 0.5);
    border-radius: 0 0 8px 8px;
  }

  /* 网格布局 */
  .grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 30px 0;
  }

  .grid-item {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
  }

  .grid-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
  }