/* Reset & CSS Variables: 斑斓彩调风 (Vibrant Colorful Style with clean light backgrounds) */
    :root {
      --primary-grad: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
      --accent-purple: #8b5cf6;
      --accent-pink: #ec4899;
      --accent-blue: #3b82f6;
      --text-dark: #0f172a;
      --text-muted: #4b5563;
      --bg-base: #f8fafc;
      --bg-card: #ffffff;
      --border-color: rgba(226, 232, 240, 0.8);
      --container-width: 1200px;
      --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-base);
      color: var(--text-dark);
      line-height: 1.6;
      overflow-x: hidden;
      scroll-behavior: smooth;
    }

    /* Common Container */
    .container {
      max-width: var(--container-width);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* Typography */
    h1, h2, h3, h4 {
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 0.5em;
    }

    /* Badges */
    .badge {
      display: inline-block;
      padding: 6px 16px;
      font-size: 0.85rem;
      font-weight: 600;
      border-radius: 9999px;
      background: var(--primary-grad);
      color: #ffffff;
      margin-bottom: 12px;
      text-transform: uppercase;
      box-shadow: 0 4px 12px rgba(168, 85, 247, 0.2);
    }

    /* Buttons */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      font-size: 1rem;
      font-weight: 600;
      border-radius: 12px;
      text-decoration: none;
      transition: var(--transition);
      cursor: pointer;
      border: none;
    }

    .btn-primary {
      background: var(--primary-grad);
      color: #ffffff;
      box-shadow: 0 10px 20px rgba(168, 85, 247, 0.25);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 14px 28px rgba(168, 85, 247, 0.35);
    }

    .btn-secondary {
      background: #ffffff;
      color: var(--text-dark);
      border: 1px solid var(--border-color);
    }

    .btn-secondary:hover {
      background: #f1f5f9;
      transform: translateY(-2px);
    }

    /* Sections */
    section {
      padding: 80px 0;
      position: relative;
    }

    .section-title {
      text-align: center;
      max-width: 700px;
      margin: 0 auto 50px;
    }

    .section-title h2 {
      font-size: 2.2rem;
      background: var(--primary-grad);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      margin-bottom: 15px;
    }

    .section-title p {
      font-size: 1.1rem;
      color: var(--text-muted);
    }

    /* Header & Navigation */
    header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.9);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: 0 4px 20px rgba(0, 0, 0, 0.02);
    }

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

    .logo-wrapper {
      display: flex;
      align-items: center;
      gap: 10px;
    }

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

    .brand-name {
      font-size: 1.3rem;
      font-weight: 800;
      background: var(--primary-grad);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .nav-links {
      display: flex;
      gap: 20px;
      align-items: center;
    }

    .nav-links a {
      color: var(--text-dark);
      text-decoration: none;
      font-size: 0.95rem;
      font-weight: 500;
      transition: var(--transition);
    }

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

    .nav-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      cursor: pointer;
    }

    /* Hero Section (No Images Allowed) */
    .hero-section {
      background: radial-gradient(circle at 10% 20%, rgba(99, 102, 241, 0.08) 0%, rgba(236, 72, 153, 0.05) 90%);
      padding: 120px 0 100px;
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    .hero-glow-1 {
      position: absolute;
      top: -10%;
      left: 10%;
      width: 400px;
      height: 400px;
      background: radial-gradient(circle, rgba(168, 85, 247, 0.15) 0%, transparent 70%);
      pointer-events: none;
      filter: blur(40px);
    }

    .hero-glow-2 {
      position: absolute;
      bottom: -10%;
      right: 10%;
      width: 400px;
      height: 400px;
      background: radial-gradient(circle, rgba(6, 182, 212, 0.12) 0%, transparent 70%);
      pointer-events: none;
      filter: blur(40px);
    }

    .hero-content h1 {
      font-size: 3rem;
      max-width: 900px;
      margin: 0 auto 20px;
      background: var(--primary-grad);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-content p {
      font-size: 1.25rem;
      color: var(--text-muted);
      max-width: 700px;
      margin: 0 auto 35px;
    }

    .hero-cta {
      display: flex;
      justify-content: center;
      gap: 15px;
      flex-wrap: wrap;
    }

    /* Stats Grid */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 60px;
    }

    .stat-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      text-align: center;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

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

    .stat-num {
      font-size: 2rem;
      font-weight: 800;
      color: var(--accent-purple);
      margin-bottom: 8px;
    }

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

    /* Service Cards (Grid) */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 25px;
    }

    .service-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 30px;
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

    .service-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
      border-color: rgba(168, 85, 247, 0.3);
    }

    .service-icon {
      font-size: 2rem;
      margin-bottom: 20px;
    }

    .service-card h3 {
      font-size: 1.25rem;
      margin-bottom: 12px;
    }

    .service-card p {
      color: var(--text-muted);
      font-size: 0.95rem;
      flex-grow: 1;
      margin-bottom: 20px;
    }

    /* Cloud Tag Cloud */
    .tag-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      justify-content: center;
      margin-top: 20px;
    }

    .tag-item {
      padding: 6px 12px;
      background: #f1f5f9;
      border-radius: 6px;
      font-size: 0.8rem;
      font-weight: 600;
      color: var(--text-muted);
      transition: var(--transition);
    }

    .tag-item:hover {
      background: var(--primary-grad);
      color: #ffffff;
    }

    /* Flow Steps & Solutions */
    .steps-container {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 25px;
      position: relative;
    }

    .step-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 30px;
      position: relative;
    }

    .step-num {
      position: absolute;
      top: -20px;
      left: 30px;
      width: 40px;
      height: 40px;
      background: var(--primary-grad);
      border-radius: 50%;
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
    }

    /* Compare Table */
    .table-container {
      overflow-x: auto;
      background: var(--bg-card);
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

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

    th, td {
      padding: 16px 24px;
      border-bottom: 1px solid var(--border-color);
    }

    th {
      background: #f8fafc;
      font-weight: 700;
    }

    tr:last-child td {
      border-bottom: none;
    }

    .highlight-row {
      background: rgba(99, 102, 241, 0.03);
    }

    .recommend-badge {
      color: var(--accent-pink);
      font-weight: bold;
    }

    /* Interactive Simulator */
    .sim-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 30px;
      box-shadow: var(--shadow-md);
    }

    .sim-slider-group {
      margin-bottom: 25px;
    }

    .sim-slider-label {
      display: flex;
      justify-content: space-between;
      margin-bottom: 8px;
      font-weight: 600;
    }

    .sim-slider {
      width: 100%;
      accent-color: var(--accent-purple);
    }

    .sim-result {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      text-align: center;
      background: #f8fafc;
      padding: 20px;
      border-radius: 12px;
    }

    /* Case Section & Media */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 25px;
    }

    .case-card {
      background: var(--bg-card);
      border-radius: var(--radius);
      overflow: hidden;
      border: 1px solid var(--border-color);
      transition: var(--transition);
    }

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

    .case-img-box {
      width: 100%;
      height: 200px;
      overflow: hidden;
      background: #e2e8f0;
    }

    .case-img-box img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: var(--transition);
    }

    .case-card:hover .case-img-box img {
      transform: scale(1.05);
    }

    .case-info {
      padding: 24px;
    }

    /* Reviews (6 Column) */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 25px;
    }

    .review-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .review-card:hover {
      border-color: var(--accent-purple);
    }

    .review-meta {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 15px;
    }

    .review-avatar {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: var(--primary-grad);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
    }

    .review-text {
      color: var(--text-muted);
      font-size: 0.95rem;
    }

    /* Articles / Blog Section */
    .articles-section {
      background: #f1f5f9;
    }

    .articles-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 25px;
    }

    .article-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 24px;
      transition: var(--transition);
    }

    .article-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-3px);
    }

    .article-card a {
      color: var(--accent-purple);
      text-decoration: none;
      font-weight: 600;
      display: inline-block;
      margin-top: 15px;
    }

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

    .faq-item {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: 12px;
      margin-bottom: 15px;
      overflow: hidden;
    }

    .faq-header {
      width: 100%;
      padding: 20px 24px;
      text-align: left;
      background: none;
      border: none;
      font-size: 1.05rem;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--text-dark);
    }

    .faq-icon {
      transition: var(--transition);
      font-size: 1.2rem;
    }

    .faq-content {
      padding: 0 24px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      color: var(--text-muted);
      font-size: 0.95rem;
    }

    .faq-content.open {
      padding: 0 24px 20px;
      max-height: 200px; /* adjusted dynamically in JS */
    }

    /* Forms */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
    }

    .form-box {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 40px;
      box-shadow: var(--shadow-md);
    }

    .form-group {
      margin-bottom: 20px;
    }

    .form-group label {
      display: block;
      margin-bottom: 8px;
      font-weight: 600;
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border-radius: 8px;
      border: 1px solid var(--border-color);
      font-size: 1rem;
      background: #f8fafc;
      transition: var(--transition);
    }

    .form-control:focus {
      outline: none;
      border-color: var(--accent-purple);
      background: #ffffff;
    }

    /* Floating Customer Services */
    .float-panel {
      position: fixed;
      bottom: 30px;
      right: 30px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      z-index: 999;
    }

    .float-btn {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      background: var(--primary-grad);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      box-shadow: var(--shadow-lg);
      border: none;
      position: relative;
    }

    .qr-tooltip {
      position: absolute;
      bottom: 60px;
      right: 0;
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 15px;
      border-radius: 12px;
      box-shadow: var(--shadow-lg);
      display: none;
      width: 150px;
      text-align: center;
    }

    .qr-tooltip img {
      width: 120px;
      height: 120px;
      object-fit: contain;
    }

    .float-btn:hover .qr-tooltip {
      display: block;
    }

    /* Footer & Friend Links */
    footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 60px 0 30px;
      border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    footer a {
      color: #cbd5e1;
      text-decoration: none;
      transition: var(--transition);
    }

    footer a:hover {
      color: var(--accent-pink);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      color: #ffffff;
      margin-bottom: 20px;
      font-size: 1.1rem;
    }

    .footer-links {
      list-style: none;
    }

    .footer-links li {
      margin-bottom: 10px;
    }

    .friend-links-box {
      border-top: 1px solid rgba(255, 255, 255, 0.05);
      padding-top: 20px;
      text-align: center;
      font-size: 0.85rem;
    }

    .friend-links-box a {
      margin: 0 10px;
      display: inline-block;
    }

    .copyright {
      margin-top: 20px;
      text-align: center;
      font-size: 0.8rem;
    }

    /* Responsive */
    @media (max-width: 1024px) {
      .steps-container {
        grid-template-columns: repeat(2, 1fr);
      }
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .case-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .reviews-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: #ffffff;
        border-bottom: 1px solid var(--border-color);
        padding: 20px;
        box-shadow: var(--shadow-md);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-toggle {
        display: block;
      }
      .hero-content h1 {
        font-size: 2.2rem;
      }
      .contact-wrapper {
        grid-template-columns: 1fr;
      }
      .steps-container, .stats-grid, .case-grid, .reviews-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
    }