:root {
      --primary: #0d9488;
      --primary-dark: #0f766e;
      --primary-light: #14b8a6;
      --primary-soft: #f0fdfa;
      --accent: #0284c7;
      --text-main: #0f172a;
      --text-muted: #334155;
      --text-light: #64748b;
      --bg-page: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --border-hover: #cbd5e1;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
      --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.03);
      --radius-sm: 6px;
      --radius-md: 10px;
      --radius-lg: 16px;
      --transition: all 0.25s ease-in-out;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: var(--transition);
    }

    ul, ol {
      list-style: none;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

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

    .header-site {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-color);
    }

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

    .brand-area {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .brand-area .ai-page-logo {
      height: 38px;
      width: auto;
      object-fit: contain;
    }

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

    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
    }

    .nav-links li a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text-muted);
      padding: 8px 12px;
      border-radius: var(--radius-sm);
    }

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

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

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 9px 18px;
      font-size: 14px;
      font-weight: 600;
      border-radius: var(--radius-sm);
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      text-align: center;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
      color: #ffffff;
      box-shadow: 0 2px 4px rgba(13, 148, 136, 0.25);
    }

    .btn-primary:hover {
      background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
      transform: translateY(-1px);
      box-shadow: 0 4px 8px rgba(13, 148, 136, 0.3);
      color: #ffffff;
    }

    .btn-outline {
      background: #ffffff;
      color: var(--primary-dark);
      border-color: var(--primary);
    }

    .btn-outline:hover {
      background: var(--primary-soft);
      border-color: var(--primary-dark);
    }

    .btn-sm {
      padding: 6px 14px;
      font-size: 13px;
    }

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

    .nav-toggle span {
      display: block;
      width: 22px;
      height: 2px;
      background-color: var(--text-main);
      margin: 4px 0;
      transition: var(--transition);
    }

    .section-py {
      padding-top: 64px;
      padding-bottom: 64px;
    }

    .section-header {
      text-align: center;
      max-width: 760px;
      margin: 0 auto 48px auto;
    }

    .section-tag {
      display: inline-block;
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: var(--primary-dark);
      background: var(--primary-soft);
      padding: 4px 12px;
      border-radius: 9999px;
      border: 1px solid rgba(13, 148, 136, 0.2);
      margin-bottom: 12px;
    }

    .section-title {
      font-size: 30px;
      font-weight: 700;
      color: var(--text-main);
      line-height: 1.3;
      margin-bottom: 14px;
    }

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

    /* Hero Section (No Images as per rule) */
    .hero-section {
      background: radial-gradient(circle at 50% 0%, #ccfbf1 0%, #f0fdfa 45%, #f8fafc 100%);
      padding: 72px 0 60px 0;
      border-bottom: 1px solid var(--border-color);
      position: relative;
      overflow: hidden;
    }

    .hero-wrap {
      text-align: center;
      max-width: 860px;
      margin: 0 auto;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 16px;
      background: #ffffff;
      border: 1px solid rgba(13, 148, 136, 0.3);
      border-radius: 9999px;
      font-size: 13px;
      font-weight: 600;
      color: var(--primary-dark);
      margin-bottom: 24px;
      box-shadow: var(--shadow-sm);
    }

    .hero-badge-dot {
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 50%;
      display: inline-block;
    }

    .hero-title {
      font-size: 40px;
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.25;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
    }

    .hero-title span {
      color: var(--primary);
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-subtitle {
      font-size: 17px;
      color: var(--text-muted);
      line-height: 1.7;
      margin-bottom: 36px;
      max-width: 720px;
      margin-left: auto;
      margin-right: auto;
    }

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

    .hero-features-strip {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
      margin-top: 20px;
    }

    .hero-stat-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 18px 14px;
      border-radius: var(--radius-md);
      text-align: center;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .hero-stat-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary-light);
    }

    .hero-stat-num {
      font-size: 24px;
      font-weight: 800;
      color: var(--primary-dark);
      margin-bottom: 4px;
    }

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

    /* Grid Layouts */
    .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: 24px;
    }

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

    .card:hover {
      border-color: var(--primary-light);
      box-shadow: var(--shadow-md);
    }

    .card-icon {
      width: 44px;
      height: 44px;
      border-radius: var(--radius-sm);
      background: var(--primary-soft);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 16px;
      font-weight: 700;
      font-size: 18px;
    }

    .card-title {
      font-size: 17px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    .card-text {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    /* Platform Models Support */
    .models-section {
      background: #ffffff;
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
    }

    .model-tags-wrap {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 10px;
      margin-top: 24px;
    }

    .model-badge {
      font-size: 13px;
      font-weight: 600;
      color: var(--text-muted);
      background: #f1f5f9;
      padding: 6px 14px;
      border-radius: 9999px;
      border: 1px solid var(--border-color);
      transition: var(--transition);
    }

    .model-badge:hover {
      background: var(--primary-soft);
      color: var(--primary-dark);
      border-color: var(--primary);
    }

    /* Process steps */
    .steps-container {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }

    .step-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px 20px;
      text-align: center;
      position: relative;
    }

    .step-num {
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      font-size: 15px;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px auto;
    }

    /* Comparison Table */
    .table-container {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow-x: auto;
      box-shadow: var(--shadow-sm);
    }

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

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

    .eval-table th {
      background: #f8fafc;
      color: var(--text-main);
      font-weight: 700;
    }

    .eval-highlight {
      background: var(--primary-soft);
      color: var(--primary-dark);
      font-weight: 600;
    }

    .score-badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: #fef3c7;
      color: #b45309;
      padding: 4px 10px;
      border-radius: 9999px;
      font-weight: 700;
      font-size: 13px;
    }

    /* Showcase media cards */
    .showcase-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 24px;
      align-items: stretch;
    }

    .media-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }

    .media-card-content {
      padding: 20px;
      flex-grow: 1;
    }

    .img-wrap {
      position: relative;
      background: #e2e8f0;
      overflow: hidden;
    }

    .img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      transition: transform 0.3s ease;
    }

    .media-card:hover .img-wrap img {
      transform: scale(1.02);
    }

    /* FAQ Accordion */
    .faq-wrapper {
      max-width: 920px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

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

    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 18px 20px;
      text-align: left;
      font-size: 15px;
      font-weight: 600;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }

    .faq-icon {
      font-size: 18px;
      color: var(--primary);
      transition: transform 0.2s ease;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      background: #f8fafc;
      border-top: 1px solid transparent;
    }

    .faq-answer-inner {
      padding: 16px 20px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    .faq-item.active .faq-answer {
      max-height: 300px;
      border-top-color: var(--border-color);
    }

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

    /* Form Section */
    .form-wrapper {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 36px;
      box-shadow: var(--shadow-sm);
      max-width: 760px;
      margin: 0 auto;
    }

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

    .form-group label {
      display: block;
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 6px;
    }

    .form-control {
      width: 100%;
      padding: 11px 14px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 14px;
      color: var(--text-main);
      background: #ffffff;
      outline: none;
      transition: var(--transition);
    }

    .form-control:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 110px;
    }

    /* Article & Info Section */
    .articles-box {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
    }

    .article-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .article-link-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 10px 14px;
      background: #f8fafc;
      border-radius: var(--radius-sm);
      font-size: 14px;
      color: var(--text-muted);
      border: 1px solid transparent;
    }

    .article-link-item:hover {
      background: var(--primary-soft);
      border-color: rgba(13, 148, 136, 0.2);
      color: var(--primary-dark);
    }

    /* Testimonials */
    .testimonial-card {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .reviewer-meta {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 16px;
      padding-top: 16px;
      border-top: 1px solid var(--border-color);
    }

    .reviewer-avatar {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: var(--primary-soft);
      color: var(--primary-dark);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 14px;
    }

    .reviewer-name {
      font-size: 14px;
      font-weight: 700;
      color: var(--text-main);
    }

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

    /* Footer */
    .site-footer {
      background: #0f172a;
      color: #94a3b8;
      padding-top: 56px;
      padding-bottom: 32px;
      border-top: 1px solid #1e293b;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 36px;
      margin-bottom: 40px;
    }

    .footer-brand h4 {
      color: #ffffff;
      font-size: 18px;
      margin-bottom: 12px;
    }

    .footer-desc {
      font-size: 13px;
      line-height: 1.7;
      margin-bottom: 16px;
      color: #cbd5e1;
    }

    .footer-col h5 {
      color: #ffffff;
      font-size: 15px;
      margin-bottom: 16px;
      font-weight: 600;
    }

    .footer-col ul {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .footer-col ul li a {
      color: #94a3b8;
      font-size: 13px;
    }

    .footer-col ul li a:hover {
      color: #14b8a6;
    }

    .footer-qrcode {
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      gap: 8px;
    }

    .footer-qrcode img {
      width: 100px;
      height: 100px;
      background: #ffffff;
      padding: 4px;
      border-radius: var(--radius-sm);
    }

    .footer-qrcode span {
      font-size: 12px;
      color: #cbd5e1;
    }

    .friend-links-box {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      margin-bottom: 24px;
    }

    .friend-links-title {
      font-size: 13px;
      font-weight: 600;
      color: #cbd5e1;
      margin-bottom: 12px;
    }

    .friend-links-list {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }

    .friend-links-list a {
      font-size: 13px;
      color: #94a3b8;
    }

    .friend-links-list a:hover {
      color: #14b8a6;
    }

    .footer-bottom {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      text-align: center;
      font-size: 13px;
      color: #64748b;
    }

    /* Floating Customer Service */
    .float-service {
      position: fixed;
      right: 20px;
      bottom: 40px;
      z-index: 99;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-lg);
      cursor: pointer;
      position: relative;
      transition: var(--transition);
      border: none;
    }

    .float-btn:hover {
      background: var(--primary-dark);
      transform: scale(1.05);
    }

    .float-qr-popup {
      position: absolute;
      right: 60px;
      bottom: 0;
      background: #ffffff;
      padding: 12px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--border-color);
      display: none;
      width: 140px;
      text-align: center;
    }

    .float-qr-popup img {
      width: 100%;
      height: auto;
      margin-bottom: 6px;
    }

    .float-qr-popup span {
      font-size: 12px;
      color: var(--text-main);
      font-weight: 600;
    }

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

    /* Responsive */
    @media (max-width: 992px) {
      .grid-4, .hero-features-strip, .steps-container {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .showcase-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-title {
        font-size: 32px;
      }
    }

    @media (max-width: 768px) {
      .nav-links, .nav-actions {
        display: none;
      }
      .nav-links.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        border-bottom: 1px solid var(--border-color);
        padding: 16px;
        gap: 8px;
        box-shadow: var(--shadow-md);
      }
      .nav-toggle {
        display: block;
      }
      .grid-2, .grid-3, .grid-4, .hero-features-strip, .steps-container {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .hero-title {
        font-size: 26px;
      }
      .form-wrapper {
        padding: 20px;
      }
    }