/* 全局样式设置 */
  body {
    margin: 0;
    font-family: 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    color: #333;
    background: linear-gradient(135deg, #1A237E 70%, #6200EA 25%, #388E3C 5%);
    overflow-x: hidden;
  }

  /* 导航栏样式 */
  .navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(26, 35, 126, 0.9);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: background 0.3s ease;
  }

  .navbar:hover {
    background: rgba(98, 0, 234, 0.9);
  }

  .navbar-logo {
    font-size: 1.5em;
    color: #fff;
    text-decoration: none;
    font-weight: bold;
  }

  .navbar-menu {
    display: flex;
    gap: 20px;
  }

  .navbar-menu a {
    color: #fff;
    text-decoration: none;
    font-size: 1em;
    position: relative;
    transition: color 0.3s ease;
  }

  .navbar-menu a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    background: #FF5722;
    left: 0;
    bottom: -5px;
    transition: width 0.3s ease;
  }

  .navbar-menu a:hover::after {
    width: 100%;
  }

  /* 主标题样式 */
  .hero {
    height: 100vh;
    background: url('https://images.gptkong.com/demo/sample1.png') center center / cover no-repeat;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    color: #fff;
    text-align: center;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(26, 35, 126, 0.7);
  }

  .hero-content {
    position: relative;
    z-index: 1;
  }

  .hero h1 {
    font-size: 3em;
    margin-bottom: 20px;
    animation: fadeInDown 2s ease-out;
  }

  .hero p {
    font-size: 1.2em;
    animation: fadeInUp 2s ease-out;
  }

  /* 章节导航样式 */
  .section-nav {
    position: fixed;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 999;
  }

  .section-nav a {
    background: #FF5722;
    color: #fff;
    padding: 10px;
    border-radius: 50%;
    text-decoration: none;
    font-size: 0.8em;
    transition: background 0.3s ease, transform 0.3s ease;
  }

  .section-nav a:hover {
    background: #388E3C;
    transform: scale(1.1);
  }

  /* 内容模块样式 */
  .container {
    padding: 100px 40px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
  }

  .module {
    background: rgba(255, 255, 255, 0.8);
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .module:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
  }

  .module img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
  }

  .module img:hover {
    transform: scale(1.05);
  }

  .module h2, .module h3, .module h4 {
    color: #1A237E;
  }

  .module p {
    line-height: 1.6;
  }

  /* 代码块样式 */
  pre {
    background: #f4f4f4;
    padding: 15px;
    border-radius: 8px;
    overflow-x: auto;
  }

  code {
    font-family: 'Courier New', Courier, monospace;
    color: #388E3C;
  }

  /* 按钮样式 */
  .cta-button {
    background: linear-gradient(45deg, #388E3C, #FF5722);
    color: #fff;
    padding: 15px 30px;
    border: none;
    border-radius: 25px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    text-decoration: none;
    display: inline-block;
  }

  .cta-button:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 8px rgba(0,0,0,0.15);
  }

  /* 回到顶部按钮 */
  .back-to-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    background: #6200EA;
    color: #fff;
    padding: 10px 15px;
    border-radius: 50%;
    text-decoration: none;
    font-size: 1.2em;
    display: none;
    transition: background 0.3s ease;
  }

  .back-to-top:hover {
    background: #1A237E;
  }

  /* 弹出折叠区域 */
  .collapsible {
    background-color: #e0e0e0;
    color: #1A237E;
    cursor: pointer;
    padding: 10px;
    width: 100%;
    border: none;
    text-align: left;
    outline: none;
    font-size: 1em;
    border-radius: 5px;
    transition: background 0.3s ease;
  }

  .active, .collapsible:hover {
    background-color: #6200EA;
    color: #fff;
  }

  .content {
    padding: 0 18px;
    display: none;
    overflow: hidden;
    background-color: #f9f9f9;
    border-radius: 5px;
    margin-top: 5px;
  }

  /* 关键帧动画 */
  @keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
  }

  @keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
  }

  /* 响应式设计 */
  @media (max-width: 768px) {
    .navbar {
      flex-direction: column;
      padding: 10px 20px;
    }

    .navbar-menu {
      flex-direction: column;
      gap: 10px;
      display: none;
    }

    .navbar-menu.active {
      display: flex;
    }

    .section-nav {
      flex-direction: row;
      bottom: 20px;
      top: auto;
      right: 50%;
      transform: translateX(50%);
    }

    .container {
      padding: 80px 20px;
      gap: 20px;
    }
  }

  /* 提示文字样式 */
  .reference-note {
    text-align: center;
    font-size: 1.2em;
    color: #fff;
    margin: 20px 0;
    animation: fadeIn 2s ease-in-out;
  }

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