/* 霓虹亮彩风 (Neon Light Theme) Base Setup */
        :root {
            --primary: #6366f1;
            --primary-neon: #4f46e5;
            --neon-cyan: #06b6d4;
            --neon-pink: #ec4899;
            --neon-purple: #8b5cf6;
            --bg-main: #f8fafc;
            --bg-card: #ffffff;
            --text-main: #0f172a;
            --text-muted: #475569;
            --border-color: #e2e8f0;
            --shadow-neon: 0 10px 25px -5px rgba(99, 102, 241, 0.15), 0 8px 10px -6px rgba(236, 72, 153, 0.1);
            --radius-lg: 16px;
            --radius-md: 10px;
            --container-max: 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-main);
            line-height: 1.6;
        }

        body {
            overflow-x: hidden;
            width: 100%;
        }

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

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

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

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

        .neon-badge {
            display: inline-block;
            padding: 4px 12px;
            font-size: 0.85rem;
            font-weight: 600;
            border-radius: 50px;
            background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(236, 72, 153, 0.1));
            color: var(--primary-neon);
            border: 1px solid rgba(99, 102, 241, 0.2);
            margin-bottom: 12px;
        }

        .section-header {
            text-align: center;
            margin-bottom: 48px;
        }

        .section-header h2 {
            font-size: 2rem;
            margin-bottom: 12px;
            background: linear-gradient(135deg, #1e293b 0%, #4f46e5 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .section-header p {
            color: var(--text-muted);
            max-width: 680px;
            margin: 0 auto;
            font-size: 1.05rem;
        }

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

        .btn-neon {
            background: linear-gradient(135deg, var(--primary) 0%, var(--neon-purple) 100%);
            color: #ffffff;
            box-shadow: 0 4px 15px rgba(99, 102, 241, 0.35);
        }

        .btn-neon:hover {
            color: #ffffff;
            transform: translateY(-2px);
            box-shadow: 0 8px 25px rgba(139, 92, 246, 0.5);
        }

        .btn-outline {
            background: #ffffff;
            color: var(--text-main);
            border: 2px solid var(--border-color);
        }

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

        /* 1. Navbar Header */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--border-color);
        }

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

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

        .ai-page-logo {
            height: 40px;
            width: auto;
            display: block;
        }

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

        .nav-links li a {
            padding: 8px 14px;
            font-size: 0.95rem;
            color: var(--text-muted);
            font-weight: 500;
        }

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

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

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

        /* 2. Hero Section (NO IMAGES HERE) */
        .hero-section {
            padding: 80px 0 60px;
            background: radial-gradient(circle at 50% 0%, rgba(99, 102, 241, 0.08) 0%, rgba(248, 250, 252, 0) 70%);
            text-align: center;
            position: relative;
        }

        .hero-content {
            max-width: 900px;
            margin: 0 auto;
        }

        .neon-title {
            font-size: 2.5rem;
            margin-bottom: 20px;
            letter-spacing: -0.5px;
            background: linear-gradient(135deg, #0f172a 0%, #4338ca 50%, #ec4899 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .hero-desc {
            font-size: 1.15rem;
            color: var(--text-muted);
            margin-bottom: 32px;
            line-height: 1.8;
        }

        .hero-actions {
            display: flex;
            gap: 16px;
            justify-content: center;
            flex-wrap: wrap;
            margin-bottom: 40px;
        }

        .hero-features-bar {
            display: flex;
            justify-content: center;
            gap: 24px;
            flex-wrap: wrap;
            padding: 16px;
            background: #ffffff;
            border-radius: var(--radius-md);
            border: 1px solid var(--border-color);
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
        }

        .hero-feature-item {
            display: flex;
            align-items: center;
            gap: 8px;
            font-size: 0.9rem;
            font-weight: 600;
            color: var(--text-main);
        }

        .hero-feature-item span {
            color: var(--neon-cyan);
        }

        /* Section Layouts */
        .section-padding {
            padding: 70px 0;
            border-bottom: 1px solid rgba(226, 232, 240, 0.6);
        }

        .bg-light-card {
            background-color: #ffffff;
        }

        /* Cards Grid Standard */
        .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;
        }

        /* 3. Metrics Cards */
        .metric-card {
            background: #ffffff;
            padding: 24px;
            border-radius: var(--radius-md);
            border: 1px solid var(--border-color);
            text-align: center;
            box-shadow: var(--shadow-neon);
            transition: transform 0.3s ease;
        }

        .metric-card:hover {
            transform: translateY(-4px);
        }

        .metric-num {
            font-size: 2.2rem;
            font-weight: 800;
            color: var(--primary-neon);
            margin-bottom: 4px;
        }

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

        /* Service Cards */
        .service-card {
            background: #ffffff;
            padding: 28px;
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-color);
            box-shadow: 0 4px 15px rgba(0,0,0,0.02);
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
        }

        .service-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 4px;
            background: linear-gradient(90deg, var(--neon-cyan), var(--neon-pink));
            opacity: 0;
            transition: opacity 0.3s ease;
        }

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

        .service-card:hover::before {
            opacity: 1;
        }

        .service-card h3 {
            font-size: 1.25rem;
            margin-bottom: 10px;
        }

        .service-card p {
            font-size: 0.95rem;
            color: var(--text-muted);
            line-height: 1.6;
        }

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

        .model-tag {
            background: rgba(99, 102, 241, 0.06);
            border: 1px solid rgba(99, 102, 241, 0.15);
            color: var(--text-main);
            padding: 6px 14px;
            border-radius: 20px;
            font-size: 0.88rem;
            font-weight: 500;
        }

        /* 4. Comparison Table Section */
        .table-responsive {
            overflow-x: auto;
            background: #ffffff;
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-color);
            box-shadow: var(--shadow-neon);
        }

        .comp-table {
            width: 100%;
            border-collapse: collapse;
            text-align: left;
            min-width: 650px;
        }

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

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

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

        .rating-badge {
            background: linear-gradient(135deg, #f59e0b, #ec4899);
            color: #fff;
            padding: 4px 10px;
            border-radius: 6px;
            font-weight: 700;
            display: inline-block;
        }

        /* Process Steps */
        .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;
        }

        .step-num {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background: var(--primary-neon);
            color: #ffffff;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            margin: 0 auto 16px;
            box-shadow: 0 0 12px rgba(79, 70, 229, 0.4);
        }

        /* Reviews Cards */
        .review-card {
            background: #ffffff;
            padding: 24px;
            border-radius: var(--radius-md);
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 10px rgba(0,0,0,0.02);
        }

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

        .avatar-placeholder {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--neon-cyan), var(--primary));
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
        }

        .review-role {
            font-size: 0.85rem;
            color: var(--text-muted);
        }

        /* FAQ Accordion */
        .faq-list {
            max-width: 840px;
            margin: 0 auto;
        }

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

        .faq-question {
            width: 100%;
            padding: 18px 24px;
            text-align: left;
            background: none;
            border: none;
            font-size: 1.05rem;
            font-weight: 600;
            color: var(--text-main);
            display: flex;
            justify-content: space-between;
            align-items: center;
            cursor: pointer;
        }

        .faq-answer {
            padding: 0 24px 18px;
            color: var(--text-muted);
            font-size: 0.98rem;
            display: none;
            line-height: 1.7;
        }

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

        .faq-item.active .faq-icon {
            transform: rotate(180deg);
        }

        .faq-icon {
            transition: transform 0.25s ease;
        }

        /* Articles & Links Grid */
        .article-card {
            background: #ffffff;
            padding: 20px;
            border-radius: var(--radius-md);
            border: 1px solid var(--border-color);
        }

        .article-card h4 {
            font-size: 1.1rem;
            margin-bottom: 8px;
        }

        .article-card a {
            color: var(--primary-neon);
            font-weight: 500;
        }

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

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

        .form-group label {
            display: block;
            font-size: 0.9rem;
            font-weight: 600;
            margin-bottom: 8px;
        }

        .form-control {
            width: 100%;
            padding: 12px 16px;
            border: 1px solid var(--border-color);
            border-radius: var(--radius-md);
            font-size: 0.95rem;
            transition: border-color 0.25s;
        }

        .form-control:focus {
            outline: none;
            border-color: var(--primary-neon);
        }

        .contact-info-box {
            display: flex;
            flex-direction: column;
            gap: 16px;
        }

        .qr-area {
            margin-top: 10px;
            text-align: center;
            padding: 16px;
            background: var(--bg-main);
            border-radius: var(--radius-md);
            width: fit-content;
        }

        .qr-area img {
            width: 140px;
            height: 140px;
            object-fit: cover;
            border-radius: 8px;
        }

        /* Footer */
        .site-footer {
            background: #0f172a;
            color: #94a3b8;
            padding: 50px 0 30px;
            border-top: 1px solid #1e293b;
        }

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

        .footer-col h4 {
            color: #ffffff;
            font-size: 1.1rem;
            margin-bottom: 16px;
        }

        .footer-col a {
            color: #94a3b8;
            display: block;
            margin-bottom: 8px;
            font-size: 0.9rem;
        }

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

        .friend-links {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
        }

        .friend-links a {
            color: #cbd5e1;
            background: #1e293b;
            padding: 4px 10px;
            border-radius: 4px;
            font-size: 0.85rem;
        }

        .copyright-bar {
            text-align: center;
            padding-top: 24px;
            border-top: 1px solid #1e293b;
            font-size: 0.88rem;
        }

        /* Floating Controls */
        .floating-kefu {
            position: fixed;
            bottom: 30px;
            right: 30px;
            z-index: 999;
            background: linear-gradient(135deg, var(--neon-pink), var(--primary));
            color: #fff;
            padding: 12px 20px;
            border-radius: 50px;
            box-shadow: 0 8px 20px rgba(236, 72, 153, 0.4);
            display: flex;
            align-items: center;
            gap: 8px;
            cursor: pointer;
            font-weight: 600;
        }

        .floating-kefu:hover {
            color: #ffffff;
            transform: scale(1.05);
        }

        /* Responsive Breakpoints */
        @media (max-width: 992px) {
            .grid-4, .grid-3 {
                grid-template-columns: repeat(2, 1fr);
            }
            .process-steps {
                grid-template-columns: repeat(2, 1fr);
            }
            .contact-wrapper {
                grid-template-columns: 1fr;
            }
            .footer-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 768px) {
            .neon-title {
                font-size: 1.8rem;
            }
            .grid-2, .grid-3, .grid-4, .process-steps {
                grid-template-columns: 1fr;
            }
            .nav-links {
                display: none;
                position: absolute;
                top: 72px;
                left: 0;
                width: 100%;
                background: #ffffff;
                flex-direction: column;
                padding: 20px;
                box-shadow: 0 10px 20px rgba(0,0,0,0.1);
            }
            .nav-links.active {
                display: flex;
            }
            .menu-toggle {
                display: block;
            }
            .footer-grid {
                grid-template-columns: 1fr;
            }
        }