/* CSS Reset & Variables - 宝蓝明艳风 */
    :root {
      --primary: #1d4ed8;
      --primary-hover: #1e40af;
      --primary-light: #eff6ff;
      --secondary: #0284c7;
      --accent: #2563eb;
      --text-dark: #0f172a;
      --text-body: #334155;
      --text-muted: #64748b;
      --bg-main: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #e2e8f0;
      --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -1px rgba(15, 23, 42, 0.04);
      --shadow-lg: 0 10px 15px -3px rgba(29, 78, 216, 0.1), 0 4px 6px -2px rgba(29, 78, 216, 0.05);
      --radius: 12px;
      --max-width: 1200px;
    }

    * {
      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;
      background-color: var(--bg-main);
      color: var(--text-body);
      line-height: 1.6;
    }

    body {
      background-color: var(--bg-main);
      overflow-x: hidden;
    }

    /* Standard Layout Container */
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    a {
      color: var(--primary);
      text-decoration: none;
      transition: color 0.2s ease;
    }

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

    /* Buttons */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      font-size: 1rem;
      font-weight: 600;
      border-radius: 8px;
      transition: all 0.3s ease;
      cursor: pointer;
      border: none;
    }

    .btn-primary {
      background-color: var(--primary);
      color: #ffffff !important;
      box-shadow: 0 4px 14px rgba(29, 78, 216, 0.35);
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(29, 78, 216, 0.45);
    }

    .btn-secondary {
      background-color: #ffffff;
      color: var(--primary) !important;
      border: 2px solid var(--primary);
    }

    .btn-secondary:hover {
      background-color: var(--primary-light);
      transform: translateY(-2px);
    }

    /* Section Titles */
    .section {
      padding: 70px 0;
      position: relative;
    }

    .section-header {
      text-align: center;
      max-width: 800px;
      margin: 0 auto 50px;
    }

    .section-subtitle {
      color: var(--primary);
      font-weight: 700;
      font-size: 0.95rem;
      text-transform: uppercase;
      letter-spacing: 1.5px;
      margin-bottom: 8px;
    }

    .section-title {
      font-size: 2.2rem;
      color: var(--text-dark);
      font-weight: 800;
      line-height: 1.3;
      margin-bottom: 16px;
    }

    .section-desc {
      color: var(--text-muted);
      font-size: 1.05rem;
    }

    /* Top Nav */
    .header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

    .nav-wrapper {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 76px;
    }

    .brand-group {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .ai-page-logo {
      height: 42px;
      width: auto;
      object-fit: contain;
    }

    .ai-page-home-link {
      font-weight: 700;
      font-size: 1rem;
      color: var(--text-dark);
      padding: 6px 12px;
      border-radius: 6px;
      background: var(--primary-light);
    }

    .nav-links {
      display: flex;
      gap: 20px;
      list-style: none;
      align-items: center;
    }

    .nav-links a {
      color: var(--text-body);
      font-weight: 500;
      font-size: 0.95rem;
    }

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

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

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

    /* Hero Section - STRICTLY NO IMAGES */
    .hero-section {
      background: linear-gradient(135deg, #1e3a8a 0%, #1d4ed8 50%, #0284c7 100%);
      color: #ffffff;
      padding: 90px 0 100px;
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    .hero-badge {
      display: inline-block;
      background: rgba(255, 255, 255, 0.18);
      border: 1px solid rgba(255, 255, 255, 0.3);
      padding: 6px 18px;
      border-radius: 50px;
      font-size: 0.9rem;
      font-weight: 600;
      margin-bottom: 24px;
      color: #ffffff;
    }

    .hero-title {
      font-size: 3rem;
      font-weight: 900;
      color: #ffffff;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
      line-height: 1.25;
    }

    .hero-subtitle {
      font-size: 1.25rem;
      color: rgba(255, 255, 255, 0.9);
      max-width: 860px;
      margin: 0 auto 36px;
      font-weight: 400;
    }

    .hero-actions {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 45px;
      flex-wrap: wrap;
    }

    .hero-actions .btn-hero-primary {
      background: #ffffff;
      color: var(--primary) !important;
      font-size: 1.1rem;
      padding: 14px 36px;
      box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
    }

    .hero-actions .btn-hero-primary:hover {
      background: #f8fafc;
      transform: translateY(-2px);
    }

    .hero-actions .btn-hero-secondary {
      background: rgba(255, 255, 255, 0.15);
      border: 1px solid rgba(255, 255, 255, 0.4);
      color: #ffffff !important;
      font-size: 1.1rem;
      padding: 14px 32px;
    }

    .hero-actions .btn-hero-secondary:hover {
      background: rgba(255, 255, 255, 0.25);
    }

    .hero-features {
      display: flex;
      justify-content: center;
      gap: 24px;
      flex-wrap: wrap;
    }

    .hero-feature-pill {
      background: rgba(0, 0, 0, 0.15);
      backdrop-filter: blur(4px);
      padding: 8px 18px;
      border-radius: 30px;
      font-size: 0.9rem;
      border: 1px solid rgba(255, 255, 255, 0.15);
    }

    /* Grid Layout Helper */
    .grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
    .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
    .grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

    /* Card Component */
    .card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
    }

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

    .card-icon {
      width: 50px;
      height: 50px;
      border-radius: 10px;
      background: var(--primary-light);
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 18px;
    }

    .card-title {
      font-size: 1.25rem;
      color: var(--text-dark);
      font-weight: 700;
      margin-bottom: 10px;
    }

    .card-desc {
      color: var(--text-body);
      font-size: 0.95rem;
    }

    /* Table Component */
    .table-container {
      width: 100%;
      overflow-x: auto;
      background: #ffffff;
      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 20px;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.95rem;
    }

    th {
      background-color: var(--primary-light);
      color: var(--text-dark);
      font-weight: 700;
    }

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

    tr:hover td {
      background-color: #f1f5f9;
    }

    /* Models Tag Cloud */
    .tag-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
    }

    .tag-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      color: var(--text-dark);
      padding: 8px 16px;
      border-radius: 20px;
      font-weight: 600;
      font-size: 0.9rem;
      box-shadow: var(--shadow-sm);
      transition: all 0.2s ease;
    }

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

    /* Rating Highlight Box */
    .rating-box {
      background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
      color: #ffffff;
      padding: 30px;
      border-radius: var(--radius);
      text-align: center;
      margin-bottom: 30px;
    }

    .rating-score {
      font-size: 3.5rem;
      font-weight: 900;
      line-height: 1;
      margin-bottom: 8px;
    }

    .rating-stars {
      color: #f59e0b;
      font-size: 1.8rem;
      margin-bottom: 10px;
    }

    /* Form Styles */
    .form-group {
      margin-bottom: 20px;
    }

    .form-label {
      display: block;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-dark);
    }

    .form-input, .form-select, .form-textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 1rem;
      outline: none;
      transition: border-color 0.2s;
      background: #ffffff;
    }

    .form-input:focus, .form-select:focus, .form-textarea:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.15);
    }

    /* FAQ Accordion */
    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      margin-bottom: 12px;
      overflow: hidden;
    }

    .faq-question {
      padding: 18px 24px;
      font-weight: 700;
      color: var(--text-dark);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #ffffff;
    }

    .faq-answer {
      padding: 0 24px 18px;
      color: var(--text-body);
      display: none;
      font-size: 0.95rem;
      border-top: 1px solid #f1f5f9;
      padding-top: 14px;
    }

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

    .faq-icon {
      font-weight: bold;
      color: var(--primary);
      transition: transform 0.3s;
    }

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

    /* Case Image Grid */
    .image-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 20px;
    }

    .image-card {
      background: #ffffff;
      border-radius: var(--radius);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

    .image-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
      display: block;
    }

    .image-card-body {
      padding: 16px;
    }

    /* Footer */
    .footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 60px 0 30px;
      border-top: 1px solid #1e293b;
    }

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

    .footer-brand h3 {
      color: #ffffff;
      font-size: 1.3rem;
      margin-bottom: 14px;
    }

    .footer-links-title {
      color: #ffffff;
      font-weight: 700;
      margin-bottom: 16px;
    }

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

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

    .footer-links-list a {
      color: #94a3b8;
    }

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

    .friend-links-box {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      margin-top: 24px;
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 0.88rem;
    }

    .friend-links-box a {
      color: #94a3b8;
    }

    .friend-links-box a:hover {
      color: #ffffff;
    }

    .copyright-bar {
      border-top: 1px solid #1e293b;
      padding-top: 24px;
      text-align: center;
      font-size: 0.85rem;
      color: #64748b;
    }

    /* Floating Customer Bar */
    .float-kefu {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius);
      box-shadow: var(--shadow-lg);
      padding: 12px;
      text-align: center;
      max-width: 150px;
    }

    .float-kefu img {
      width: 110px;
      height: 110px;
      object-fit: cover;
      border-radius: 6px;
      display: block;
      margin: 0 auto 8px;
    }

    .float-kefu-text {
      font-size: 0.8rem;
      font-weight: 700;
      color: var(--text-dark);
    }

    /* Responsive */
    @media (max-width: 992px) {
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
      .hero-title { font-size: 2.2rem; }
    }

    @media (max-width: 768px) {
      .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
      .nav-links { display: none; }
      .mobile-menu-btn { display: block; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-title { font-size: 1.8rem; }
      .float-kefu { display: none; } /* hide on tiny screens to optimize UI */
    }