:root {
      --primary: #10b981;
      --primary-dark: #059669;
      --primary-light: #d1fae5;
      --primary-subtle: #ecfdf5;
      --accent: #06b6d4;
      --bg-main: #f4faf7;
      --bg-surface: #ffffff;
      --bg-card: #ffffff;
      --text-main: #132e27;
      --text-muted: #4b6358;
      --text-light: #718b80;
      --border-color: #d8ebe1;
      --border-light: #e6f4ed;
      --shadow-sm: 0 2px 8px rgba(16, 185, 129, 0.06);
      --shadow-md: 0 8px 24px rgba(16, 185, 129, 0.08);
      --shadow-lg: 0 16px 36px rgba(16, 185, 129, 0.12);
      --radius: 12px;
      --radius-sm: 6px;
      --radius-lg: 20px;
      --transition: all 0.28s ease;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-main);
      color: var(--text-main);
      line-height: 1.65;
      overflow-x: hidden;
    }

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    /* Header & Navigation */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.94);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      box-shadow: var(--shadow-sm);
    }

    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .brand-box {
      display: flex;
      align-items: center;
      gap: 12px;
      text-decoration: none;
    }

    .brand-box .ai-page-logo {
      height: 38px;
      width: auto;
      display: block;
    }

    .brand-title {
      font-size: 20px;
      font-weight: 700;
      color: var(--text-main);
      letter-spacing: -0.5px;
    }

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

    .nav-links a {
      color: var(--text-muted);
      text-decoration: none;
      font-size: 14px;
      font-weight: 500;
      padding: 8px 12px;
      border-radius: var(--radius-sm);
      transition: var(--transition);
      display: inline-block;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-dark);
      background: var(--primary-subtle);
    }

    .nav-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .btn-nav-portal {
      background: var(--primary);
      color: #ffffff;
      padding: 9px 18px;
      border-radius: 30px;
      text-decoration: none;
      font-size: 14px;
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(16, 185, 129, 0.25);
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }

    .btn-nav-portal:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
    }

    .mobile-menu-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 6px;
    }

    .mobile-menu-toggle span {
      display: block;
      width: 22px;
      height: 2px;
      background: var(--text-main);
      margin: 5px 0;
      transition: var(--transition);
    }

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

    .section-header {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 50px auto;
    }

    .badge-pill {
      display: inline-block;
      background: var(--primary-subtle);
      color: var(--primary-dark);
      border: 1px solid var(--border-color);
      font-size: 13px;
      font-weight: 600;
      padding: 4px 14px;
      border-radius: 20px;
      margin-bottom: 12px;
    }

    .section-header h2 {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 14px;
      letter-spacing: -0.5px;
    }

    .section-header p {
      font-size: 15px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* Hero Section (No Image strictly) */
    .hero-section {
      padding: 90px 0 70px 0;
      background: linear-gradient(180deg, #e8f7f0 0%, #f4faf7 100%);
      text-align: center;
      position: relative;
    }

    .hero-pill {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(255, 255, 255, 0.9);
      padding: 6px 16px;
      border-radius: 30px;
      border: 1px solid var(--border-color);
      font-size: 13px;
      color: var(--text-muted);
      margin-bottom: 24px;
    }

    .hero-dot {
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 50%;
      box-shadow: 0 0 0 4px var(--primary-light);
    }

    .hero-title {
      font-size: 42px;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.25;
      margin-bottom: 20px;
      letter-spacing: -0.8px;
    }

    .hero-desc {
      font-size: 17px;
      color: var(--text-muted);
      max-width: 820px;
      margin: 0 auto 36px auto;
      line-height: 1.75;
    }

    .hero-cta-group {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }

    .btn-hero-primary {
      background: var(--primary);
      color: #ffffff;
      font-size: 16px;
      font-weight: 700;
      padding: 14px 34px;
      border-radius: 40px;
      text-decoration: none;
      box-shadow: 0 8px 24px rgba(16, 185, 129, 0.35);
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      gap: 8px;
    }

    .btn-hero-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 12px 28px rgba(16, 185, 129, 0.4);
    }

    .btn-hero-secondary {
      background: #ffffff;
      color: var(--text-main);
      font-size: 16px;
      font-weight: 600;
      padding: 14px 30px;
      border-radius: 40px;
      border: 1px solid var(--border-color);
      text-decoration: none;
      transition: var(--transition);
    }

    .btn-hero-secondary:hover {
      background: var(--primary-subtle);
      border-color: var(--primary);
      color: var(--primary-dark);
    }

    .hero-stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      max-width: 1000px;
      margin: 0 auto;
    }

    .stat-card {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 20px 16px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .stat-card:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary-light);
    }

    .stat-num {
      font-size: 26px;
      font-weight: 800;
      color: var(--primary-dark);
      margin-bottom: 4px;
      font-family: Arial, sans-serif;
    }

    .stat-label {
      font-size: 13px;
      color: var(--text-muted);
      font-weight: 500;
    }

    /* Model Logos Grid */
    .model-strip {
      background: #ffffff;
      border-top: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
      padding: 30px 0;
    }

    .model-strip-title {
      text-align: center;
      font-size: 13px;
      font-weight: 600;
      color: var(--text-light);
      text-transform: uppercase;
      letter-spacing: 1px;
      margin-bottom: 18px;
    }

    .model-tags-container {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
    }

    .model-tag {
      background: var(--bg-main);
      color: var(--text-muted);
      border: 1px solid var(--border-light);
      font-size: 13px;
      font-weight: 500;
      padding: 6px 14px;
      border-radius: 20px;
      transition: var(--transition);
    }

    .model-tag:hover {
      background: var(--primary-subtle);
      color: var(--primary-dark);
      border-color: var(--primary-light);
    }

    /* Cards Grid Styles */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }

    .feature-card {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      height: 100%;
    }

    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary-light);
    }

    .feature-icon-box {
      width: 46px;
      height: 46px;
      border-radius: 10px;
      background: var(--primary-subtle);
      color: var(--primary-dark);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      font-weight: bold;
      margin-bottom: 18px;
    }

    .feature-card h3 {
      font-size: 18px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 10px;
    }

    .feature-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
      flex-grow: 1;
    }

    .feature-card .card-footer-meta {
      margin-top: 16px;
      padding-top: 12px;
      border-top: 1px dashed var(--border-light);
      font-size: 12px;
      color: var(--primary-dark);
      font-weight: 600;
    }

    /* Platform Showcase Section */
    .about-platform-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--shadow-sm);
    }

    .about-platform-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 36px;
      align-items: center;
    }

    .about-content h3 {
      font-size: 26px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
      line-height: 1.4;
    }

    .about-content p {
      font-size: 15px;
      color: var(--text-muted);
      line-height: 1.75;
      margin-bottom: 20px;
    }

    .about-points {
      list-style: none;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      margin-bottom: 24px;
    }

    .about-points li {
      font-size: 14px;
      color: var(--text-main);
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .about-points li::before {
      content: "✓";
      color: var(--primary);
      font-weight: 800;
    }

    .about-visual-panel {
      background: var(--bg-main);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 24px;
    }

    .visual-media-box {
      border-radius: var(--radius-sm);
      overflow: hidden;
      margin-bottom: 16px;
      border: 1px solid var(--border-color);
      background: #ffffff;
    }

    .visual-media-box img {
      width: 100%;
      height: auto;
      display: block;
      object-fit: cover;
    }

    /* Comparison Table Section */
    .compare-container {
      background: #ffffff;
      border-radius: var(--radius);
      border: 1px solid var(--border-color);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .table-responsive {
      width: 100%;
      overflow-x: auto;
    }

    .compare-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      min-width: 680px;
    }

    .compare-table th,
    .compare-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-light);
      font-size: 14px;
    }

    .compare-table th {
      background: var(--bg-main);
      font-weight: 700;
      color: var(--text-main);
    }

    .compare-table th.highlight-col,
    .compare-table td.highlight-col {
      background: var(--primary-subtle);
      color: var(--text-main);
      font-weight: 600;
      border-left: 2px solid var(--primary-light);
      border-right: 2px solid var(--primary-light);
    }

    .rating-badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      background: #fef08a;
      color: #854d0e;
      padding: 2px 10px;
      border-radius: 12px;
      font-size: 12px;
      font-weight: 700;
    }

    /* Process Timeline */
    .process-grid {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      gap: 16px;
    }

    .process-card {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 20px 16px;
      text-align: center;
      position: relative;
    }

    .process-step-num {
      width: 32px;
      height: 32px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      margin: 0 auto 12px auto;
      font-size: 14px;
    }

    .process-card h4 {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .process-card p {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.5;
    }

    /* Testimonials */
    .reviews-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
    }

    .review-card {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 24px;
      box-shadow: var(--shadow-sm);
    }

    .review-header {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
    }

    .avatar-placeholder {
      width: 42px;
      height: 42px;
      border-radius: 50%;
      background: var(--primary-light);
      color: var(--primary-dark);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 14px;
    }

    .reviewer-info h4 {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
    }

    .reviewer-info span {
      font-size: 12px;
      color: var(--text-light);
    }

    .review-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
    }

    .review-stars {
      color: #eab308;
      font-size: 13px;
      margin-bottom: 8px;
    }

    /* FAQ Accordion */
    .faq-container {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      overflow: hidden;
      transition: var(--transition);
    }

    .faq-question {
      width: 100%;
      padding: 18px 22px;
      background: none;
      border: none;
      text-align: left;
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .faq-question:hover {
      color: var(--primary-dark);
    }

    .faq-icon {
      font-size: 18px;
      color: var(--primary);
      transition: transform 0.25s ease;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out, padding 0.3s ease;
      background: var(--bg-main);
      padding: 0 22px;
    }

    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 16px 22px;
      border-top: 1px solid var(--border-light);
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    .faq-answer p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* Article Links & Info */
    .article-box {
      background: #ffffff;
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 30px;
      margin-bottom: 30px;
    }

    .article-links-list {
      list-style: none;
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 14px;
    }

    .article-links-list a {
      color: var(--text-main);
      text-decoration: none;
      font-size: 14px;
      padding: 10px 14px;
      background: var(--bg-main);
      border-radius: var(--radius-sm);
      border: 1px solid var(--border-light);
      display: block;
      transition: var(--transition);
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }

    .article-links-list a:hover {
      background: var(--primary-subtle);
      border-color: var(--primary);
      color: var(--primary-dark);
    }

    /* Form Section */
    .form-wrapper {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 40px;
      box-shadow: var(--shadow-sm);
    }

    .form-grid-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 36px;
    }

    .form-info-col h3 {
      font-size: 24px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
    }

    .form-info-col p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 24px;
    }

    .contact-item-row {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
      font-size: 14px;
      color: var(--text-main);
    }

    .contact-qr-wrapper {
      margin-top: 20px;
      display: inline-block;
      padding: 10px;
      background: var(--bg-main);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      text-align: center;
    }

    .contact-qr-wrapper img {
      width: 120px;
      height: 120px;
      display: block;
      margin: 0 auto 6px auto;
    }

    .contact-qr-wrapper span {
      font-size: 12px;
      color: var(--text-muted);
    }

    .custom-form {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .form-group label {
      font-size: 13px;
      font-weight: 600;
      color: var(--text-main);
    }

    .form-control {
      width: 100%;
      padding: 12px 14px;
      font-size: 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      background: var(--bg-main);
      color: var(--text-main);
      outline: none;
      transition: var(--transition);
      font-family: inherit;
    }

    .form-control:focus {
      background: #ffffff;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px var(--primary-light);
    }

    textarea.form-control {
      min-height: 100px;
      resize: vertical;
    }

    .btn-submit-form {
      background: var(--primary);
      color: #ffffff;
      border: none;
      padding: 13px 24px;
      border-radius: 30px;
      font-size: 15px;
      font-weight: 700;
      cursor: pointer;
      box-shadow: 0 4px 14px rgba(16, 185, 129, 0.3);
      transition: var(--transition);
    }

    .btn-submit-form:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
    }

    /* Floating Contact Widget */
    .floating-kefu {
      position: fixed;
      right: 20px;
      bottom: 80px;
      z-index: 999;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 30px;
      padding: 8px 16px;
      box-shadow: var(--shadow-md);
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
      color: var(--text-main);
      font-size: 13px;
      font-weight: 600;
      transition: var(--transition);
    }

    .floating-kefu:hover {
      background: var(--primary-subtle);
      border-color: var(--primary);
      transform: translateY(-2px);
    }

    .floating-kefu-badge {
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 50%;
    }

    /* Back to Top */
    .back-to-top {
      position: fixed;
      right: 20px;
      bottom: 24px;
      z-index: 999;
      width: 40px;
      height: 40px;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      box-shadow: var(--shadow-sm);
      color: var(--text-main);
      font-size: 16px;
      transition: var(--transition);
      opacity: 0;
      visibility: hidden;
    }

    .back-to-top.show {
      opacity: 1;
      visibility: visible;
    }

    .back-to-top:hover {
      background: var(--primary-subtle);
      color: var(--primary-dark);
    }

    /* Footer */
    .site-footer {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      padding: 50px 0 30px 0;
      color: var(--text-muted);
      font-size: 14px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 30px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      font-size: 15px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 16px;
    }

    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .footer-links a {
      color: var(--text-muted);
      text-decoration: none;
      transition: var(--transition);
    }

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

    .friend-links-box {
      border-top: 1px solid var(--border-light);
      padding-top: 20px;
      margin-bottom: 24px;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 12px;
      font-size: 13px;
    }

    .friend-links-box span {
      font-weight: 600;
      color: var(--text-main);
    }

    .friend-links-box a {
      color: var(--text-muted);
      text-decoration: none;
      transition: var(--transition);
    }

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

    .footer-bottom {
      border-top: 1px solid var(--border-light);
      padding-top: 20px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 13px;
      color: var(--text-light);
    }

    /* Responsive */
    @media (max-width: 992px) {
      .grid-3,
      .grid-4,
      .reviews-grid,
      .process-grid,
      .hero-stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .about-platform-grid,
      .form-grid-layout,
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero-title {
        font-size: 34px;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        align-items: flex-start;
        padding: 16px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links a {
        width: 100%;
        padding: 10px 12px;
      }
      .mobile-menu-toggle {
        display: block;
      }
      .grid-3,
      .grid-4,
      .grid-2,
      .reviews-grid,
      .process-grid,
      .article-links-list,
      .hero-stats-grid,
      .about-points {
        grid-template-columns: 1fr;
      }
      .hero-title {
        font-size: 28px;
      }
      .section-header h2 {
        font-size: 24px;
      }
      .footer-bottom {
        flex-direction: column;
        gap: 10px;
        text-align: center;
      }
    }