/* CSS Variables & Global Reset - 渐变青科技风 */
    :root {
      --primary: #06b6d4;
      --primary-dark: #0891b2;
      --primary-light: #ecfeff;
      --accent: #0d9488;
      --accent-gradient: linear-gradient(135deg, #06b6d4 0%, #0d9488 50%, #0284c7 100%);
      --text-main: #0f172a;
      --text-muted: #475569;
      --text-light: #64748b;
      --bg-body: #f8fafc;
      --bg-card: #ffffff;
      --border-color: #cbd5e1;
      --border-highlight: #a5f3fc;
      --shadow-sm: 0 2px 8px rgba(6, 182, 212, 0.06);
      --shadow-md: 0 10px 25px -5px rgba(6, 182, 212, 0.12), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
      --shadow-lg: 0 20px 30px -10px rgba(8, 145, 178, 0.18);
      --radius-sm: 6px;
      --radius-md: 12px;
      --radius-lg: 20px;
    }

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

    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
      background-color: var(--bg-body);
      color: var(--text-main);
      line-height: 1.6;
    }

    body {
      overflow-x: hidden;
    }

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

    /* Typography */
    h1, h2, h3, h4, h5, h6 {
      color: var(--text-main);
      font-weight: 700;
      line-height: 1.3;
    }

    p {
      color: var(--text-muted);
      margin-bottom: 1rem;
    }

    a {
      color: var(--primary-dark);
      text-decoration: none;
      transition: all 0.25s ease;
    }

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

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

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

    .section-badge {
      display: inline-block;
      padding: 4px 14px;
      background: var(--primary-light);
      color: var(--accent);
      border: 1px solid var(--border-highlight);
      border-radius: 50px;
      font-size: 0.85rem;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .section-title {
      font-size: 2.2rem;
      margin-bottom: 16px;
      position: relative;
    }

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

    /* Header Nav Styling */
    header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid rgba(203, 213, 225, 0.6);
    }

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

    .brand-logo {
      display: flex;
      align-items: center;
    }

    .ai-page-logo {
      max-height: 44px;
      width: auto;
    }

    /* STRICT REQUIREMENT: .nav-links gap must be 0 */
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0;
      list-style: none;
    }

    .nav-links li a {
      display: block;
      padding: 10px 14px;
      font-size: 0.95rem;
      font-weight: 500;
      color: var(--text-main);
      border-radius: var(--radius-sm);
    }

    .nav-links li a:hover,
    .nav-links li a.active {
      color: var(--accent);
      background: var(--primary-light);
    }

    .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-main);
      cursor: pointer;
    }

    /* Button System */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 26px;
      font-size: 1rem;
      font-weight: 600;
      border-radius: 50px;
      cursor: pointer;
      border: none;
      transition: all 0.3s ease;
      box-shadow: var(--shadow-sm);
      text-align: center;
    }

    .btn-primary {
      background: var(--accent-gradient);
      color: #ffffff !important;
    }

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

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

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

    /* Hero Section - NO IMAGES STRICT RULE */
    .hero-section {
      padding: 90px 0 70px 0;
      background: radial-gradient(circle at 70% 20%, rgba(165, 243, 252, 0.4) 0%, rgba(248, 250, 252, 1) 70%);
      overflow: hidden;
    }

    .hero-content {
      text-align: center;
      max-width: 920px;
      margin: 0 auto;
    }

    .hero-title {
      font-size: 2.8rem;
      letter-spacing: -0.5px;
      margin-bottom: 24px;
      background: linear-gradient(135deg, #0f172a 0%, #0891b2 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-subtitle {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin-bottom: 36px;
      line-height: 1.7;
    }

    .hero-actions {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 50px;
      flex-wrap: wrap;
    }

    .hero-tags {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 10px;
      margin-bottom: 50px;
    }

    .hero-tag-item {
      padding: 6px 16px;
      background: rgba(255, 255, 255, 0.8);
      border: 1px solid var(--border-highlight);
      border-radius: 20px;
      font-size: 0.88rem;
      color: var(--accent);
      font-weight: 500;
    }

    .hero-stats {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      background: #ffffff;
      padding: 30px;
      border-radius: var(--radius-lg);
      border: 1px solid #e2e8f0;
      box-shadow: var(--shadow-md);
    }

    .stat-card {
      text-align: center;
    }

    .stat-number {
      font-size: 2.2rem;
      font-weight: 800;
      color: var(--accent);
      margin-bottom: 4px;
    }

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

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

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

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

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

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

    .card-icon {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      color: var(--accent);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.4rem;
      font-weight: bold;
      margin-bottom: 18px;
    }

    .card-title {
      font-size: 1.25rem;
      margin-bottom: 10px;
    }

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

    /* About Section */
    .about-box {
      background: #ffffff;
      border-radius: var(--radius-lg);
      padding: 40px;
      border: 1px solid #e2e8f0;
      box-shadow: var(--shadow-sm);
    }

    .about-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }

    .about-list {
      list-style: none;
      margin-top: 20px;
    }

    .about-list li {
      position: relative;
      padding-left: 24px;
      margin-bottom: 12px;
      color: var(--text-muted);
    }

    .about-list li::before {
      content: "✓";
      position: absolute;
      left: 0;
      color: var(--accent);
      font-weight: bold;
    }

    /* Comparison Section */
    .rating-banner {
      background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
      color: #ffffff;
      padding: 30px;
      border-radius: var(--radius-lg);
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 30px;
      box-shadow: var(--shadow-md);
    }

    .rating-score {
      font-size: 2.8rem;
      font-weight: 800;
      color: #38bdf8;
    }

    .rating-stars {
      color: #f59e0b;
      font-size: 1.5rem;
      margin-bottom: 4px;
    }

    .table-responsive {
      width: 100%;
      overflow-x: auto;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

    .comp-table {
      width: 100%;
      border-collapse: collapse;
      background: #ffffff;
      text-align: left;
    }

    .comp-table th, .comp-table td {
      padding: 16px 20px;
      border-bottom: 1px solid #e2e8f0;
    }

    .comp-table th {
      background: #f1f5f9;
      color: var(--text-main);
      font-weight: 700;
    }

    .comp-table tr.highlight-row {
      background: var(--primary-light);
    }

    .comp-table td.brand-col {
      font-weight: 700;
      color: var(--accent);
    }

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

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

    .step-number {
      width: 40px;
      height: 40px;
      background: var(--accent-gradient);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      margin: 0 auto 16px auto;
    }

    /* Form Section */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1.2fr;
      gap: 40px;
      background: #ffffff;
      border-radius: var(--radius-lg);
      padding: 40px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
    }

    .contact-info-item {
      display: flex;
      align-items: flex-start;
      gap: 16px;
      margin-bottom: 24px;
    }

    .qr-box {
      margin-top: 20px;
      text-align: center;
      max-width: 180px;
    }

    .qr-box img {
      width: 100%;
      border-radius: var(--radius-sm);
      border: 1px solid var(--border-color);
    }

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

    .form-group label {
      display: block;
      margin-bottom: 8px;
      font-weight: 600;
      font-size: 0.95rem;
    }

    .form-control {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 1rem;
      background: #f8fafc;
      transition: all 0.3s ease;
    }

    .form-control:focus {
      outline: none;
      border-color: var(--primary);
      background: #ffffff;
      box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.15);
    }

    textarea.form-control {
      resize: vertical;
      min-height: 120px;
    }

    /* Accordion FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      transition: all 0.3s ease;
    }

    .faq-header {
      padding: 20px 24px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.05rem;
      background: #ffffff;
    }

    .faq-header:hover {
      color: var(--accent);
    }

    .faq-icon {
      font-size: 1.2rem;
      transition: transform 0.3s ease;
    }

    .faq-content {
      padding: 0 24px 20px 24px;
      display: none;
      color: var(--text-muted);
      border-top: 1px solid #f1f5f9;
      font-size: 0.98rem;
    }

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

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

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

    .review-user {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 20px;
    }

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

    /* Articles section */
    .article-item {
      padding: 16px;
      background: #ffffff;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      margin-bottom: 12px;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    /* Footer Styling - Strictly Defined Contrast */
    footer {
      background: #0f172a;
      color: #f8fafc;
      padding: 60px 0 30px 0;
      border-top: 1px solid #1e293b;
    }

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

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

    .footer-col p, .footer-col li {
      color: #94a3b8;
      font-size: 0.9rem;
      margin-bottom: 10px;
    }

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

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

    .footer-links li a:hover {
      color: #38bdf8;
    }

    .friendship-links {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      padding: 20px 0;
      border-top: 1px solid #1e293b;
      border-bottom: 1px solid #1e293b;
      margin-bottom: 30px;
    }

    .friendship-links a {
      color: #94a3b8;
      font-size: 0.88rem;
    }

    .friendship-links a:hover {
      color: #38bdf8;
    }

    .footer-bottom {
      text-align: center;
      color: #64748b;
      font-size: 0.88rem;
    }

    /* Float Service Widget */
    .float-widget {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 50px;
      height: 50px;
      background: var(--accent-gradient);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-md);
      cursor: pointer;
      font-size: 1.2rem;
      transition: transform 0.3s ease;
    }

    .float-btn:hover {
      transform: scale(1.1);
    }

    /* Mobile Responsive Breakpoints */
    @media (max-width: 992px) {
      .hero-title { font-size: 2.2rem; }
      .grid-4, .process-steps { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .about-grid, .contact-wrapper { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      
      .mobile-menu-btn { display: block; }
      .nav-links {
        display: none;
        position: absolute;
        top: 76px;
        left: 0;
        width: 100%;
        background: #ffffff;
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-md);
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.show { display: flex; }
      .nav-links li { width: 100%; text-align: center; }
    }

    @media (max-width: 640px) {
      .hero-title { font-size: 1.7rem; }
      .hero-stats { grid-template-columns: repeat(2, 1fr); }
      .grid-2, .grid-3, .grid-4, .process-steps { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .rating-banner { flex-direction: column; text-align: center; gap: 16px; }
    }