:root {
      --primary: #4f46e5;
      --primary-dark: #4338ca;
      --secondary: #06b6d4;
      --accent: #ec4899;
      --bg-light: #f8fafc;
      --surface: #ffffff;
      --text-main: #0f172a;
      --text-muted: #475569;
      --border-color: #e2e8f0;
      --radius: 12px;
      --shadow: 0 10px 25px -5px rgba(0,0,0,0.05), 0 8px 10px -6px rgba(0,0,0,0.05);
      --gradient-main: linear-gradient(135deg, #4f46e5 0%, #06b6d4 100%);
      --gradient-soft: linear-gradient(135deg, #e0e7ff 0%, #fae8ff 50%, #e0f2fe 100%);
    }

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

    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    }

    body {
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.6;
      overflow-x: hidden;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 顶部导航 */
    header {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      position: sticky;
      top: 0;
      z-index: 1000;
      border-bottom: 1px solid var(--border-color);
    }

    .nav-wrapper {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 70px;
    }

    .logo-container {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .ai-page-logo {
      height: 40px;
      width: auto;
      object-fit: contain;
    }

    .brand-name {
      font-weight: 700;
      font-size: 1.25rem;
      color: var(--text-main);
      text-decoration: none;
    }

    .nav-links {
      display: flex;
      gap: 0;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      text-decoration: none;
      color: var(--text-muted);
      font-weight: 500;
      font-size: 0.9rem;
      padding: 6px 10px;
      transition: color 0.3s;
    }

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

    .nav-cta {
      display: flex;
      gap: 10px;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 9px 18px;
      border-radius: var(--radius);
      font-weight: 600;
      text-decoration: none;
      transition: all 0.3s;
      cursor: pointer;
      border: none;
      font-size: 0.9rem;
    }

    .btn-primary {
      background: var(--gradient-main);
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
    }

    .btn-primary:hover {
      opacity: 0.95;
      transform: translateY(-2px);
    }

    .btn-outline {
      border: 1px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }

    .btn-outline:hover {
      background: rgba(79, 70, 229, 0.05);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-main);
      cursor: pointer;
    }

    /* 首屏 Hero (无图片) */
    .hero {
      background: var(--gradient-soft);
      padding: 80px 0 60px 0;
      text-align: center;
      position: relative;
    }

    .hero-badge {
      display: inline-block;
      padding: 6px 16px;
      background: #ffffff;
      border-radius: 30px;
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--primary);
      box-shadow: 0 2px 10px rgba(0,0,0,0.05);
      margin-bottom: 20px;
    }

    .hero h1 {
      font-size: 2.2rem;
      font-weight: 800;
      color: var(--text-main);
      margin-bottom: 20px;
      line-height: 1.3;
    }

    .hero p {
      font-size: 1.1rem;
      color: var(--text-muted);
      max-width: 760px;
      margin: 0 auto 30px auto;
    }

    .hero-actions {
      display: flex;
      justify-content: center;
      gap: 15px;
      margin-bottom: 40px;
    }

    .model-tags-cloud {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 8px;
      max-width: 900px;
      margin: 0 auto;
    }

    .tag-item {
      background: rgba(255,255,255,0.7);
      border: 1px solid rgba(255,255,255,0.9);
      padding: 4px 10px;
      border-radius: 6px;
      font-size: 0.75rem;
      color: var(--text-muted);
    }

    /* 通用 Section */
    section {
      padding: 70px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 50px;
    }

    .section-title h2 {
      font-size: 1.8rem;
      color: var(--text-main);
      margin-bottom: 10px;
    }

    .section-title p {
      color: var(--text-muted);
      font-size: 1rem;
    }

    /* 数据卡片 */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: 20px;
    }

    .metric-card {
      background: var(--surface);
      padding: 30px 20px;
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      text-align: center;
      border: 1px solid var(--border-color);
      transition: transform 0.3s;
    }

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

    .metric-value {
      font-size: 2.2rem;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 5px;
    }

    .metric-label {
      color: var(--text-muted);
      font-size: 0.9rem;
    }

    /* 服务与能力网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 24px;
    }

    .card {
      background: var(--surface);
      border-radius: var(--radius);
      padding: 28px;
      box-shadow: var(--shadow);
      border: 1px solid var(--border-color);
      transition: all 0.3s;
      display: flex;
      flex-direction: column;
    }

    .card:hover {
      box-shadow: 0 15px 30px -5px rgba(0,0,0,0.1);
      transform: translateY(-4px);
    }

    .card-icon {
      width: 48px;
      height: 48px;
      background: var(--gradient-soft);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 16px;
    }

    .card h3 {
      font-size: 1.2rem;
      margin-bottom: 10px;
      color: var(--text-main);
    }

    .card p {
      color: var(--text-muted);
      font-size: 0.9rem;
      flex-grow: 1;
    }

    /* 图片与展示 */
    .media-card {
      background: var(--surface);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow);
      border: 1px solid var(--border-color);
    }

    .media-card img {
      width: 100%;
      height: 220px;
      object-fit: cover;
      display: block;
    }

    .media-card-body {
      padding: 20px;
    }

    /* 流程步骤 */
    .timeline {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: 20px;
      position: relative;
    }

    .step-item {
      background: var(--surface);
      padding: 24px;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      position: relative;
    }

    .step-number {
      font-size: 1.8rem;
      font-weight: 800;
      color: rgba(79, 70, 229, 0.2);
      margin-bottom: 8px;
    }

    /* 对比表格 */
    .table-container {
      width: 100%;
      overflow-x: auto;
      background: var(--surface);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      border: 1px solid var(--border-color);
    }

    table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
    }

    th, td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }

    th {
      background: #f1f5f9;
      color: var(--text-main);
    }

    .highlight-row {
      background: #eef2ff;
      font-weight: 600;
    }

    .score-badge {
      display: inline-block;
      padding: 4px 12px;
      background: #22c55e;
      color: white;
      border-radius: 20px;
      font-size: 0.85rem;
    }

    /* 用户评论 */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 20px;
    }

    .testimonial-card {
      background: var(--surface);
      padding: 24px;
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      border: 1px solid var(--border-color);
    }

    .user-info {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 12px;
    }

    .avatar {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: var(--gradient-main);
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
    }

    .user-details h4 {
      font-size: 0.95rem;
      color: var(--text-main);
    }

    .user-details span {
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    /* FAQ */
    .faq-container {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: var(--surface);
      border-radius: var(--radius);
      margin-bottom: 12px;
      border: 1px solid var(--border-color);
      overflow: hidden;
    }

    .faq-question {
      padding: 18px 24px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: var(--surface);
      color: var(--text-main);
    }

    .faq-answer {
      padding: 0 24px 18px 24px;
      color: var(--text-muted);
      font-size: 0.9rem;
      display: none;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    /* 联系我们与表单 */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      background: var(--surface);
      padding: 40px;
      border-radius: var(--radius);
      box-shadow: var(--shadow);
      border: 1px solid var(--border-color);
    }

    .form-group {
      margin-bottom: 18px;
    }

    .form-group label {
      display: block;
      margin-bottom: 6px;
      font-weight: 500;
      font-size: 0.9rem;
    }

    .form-control {
      width: 100%;
      padding: 10px 14px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 0.95rem;
      outline: none;
    }

    .form-control:focus {
      border-color: var(--primary);
    }

    /* 页脚 */
    footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 60px 0 20px 0;
      border-top: 1px solid #1e293b;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 30px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      color: #ffffff;
      margin-bottom: 16px;
      font-size: 1rem;
    }

    .footer-col ul {
      list-style: none;
    }

    .footer-col ul li {
      margin-bottom: 8px;
    }

    .footer-col a {
      color: #94a3b8;
      text-decoration: none;
      font-size: 0.85rem;
    }

    .footer-col a:hover {
      color: #ffffff;
    }

    .footer-bottom {
      text-align: center;
      padding-top: 20px;
      border-top: 1px solid #1e293b;
      font-size: 0.85rem;
    }

    .friend-links {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      justify-content: center;
      margin-bottom: 15px;
    }

    .friend-links a {
      color: #64748b;
      text-decoration: none;
      font-size: 0.8rem;
    }

    /* 浮动客服 */
    .float-service {
      position: fixed;
      bottom: 30px;
      right: 30px;
      background: var(--surface);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow);
      border-radius: 30px;
      padding: 8px 16px;
      display: flex;
      align-items: center;
      gap: 10px;
      z-index: 999;
      cursor: pointer;
    }

    .float-service img {
      width: 28px;
      height: 28px;
      border-radius: 50%;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--surface);
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.active {
        display: flex;
      }
      .menu-toggle {
        display: block;
      }
      .hero h1 {
        font-size: 1.6rem;
      }
      .contact-wrapper {
        grid-template-columns: 1fr;
      }
    }