/* CSS Reset & Style Variables (Black & White Film Style) */
        :root {
            --bg-color: #f7f7f7;
            --container-bg: #ffffff;
            --text-primary: #111111;
            --text-secondary: #555555;
            --border-color: #222222;
            --border-light: #e0e0e0;
            --accent-color: #000000;
            --hover-bg: #ececec;
            --font-serif: "Playfair Display", Georgia, "Times New Roman", "Source Han Serif CN", serif;
            --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Microsoft YaHei", sans-serif;
            --transition-speed: 0.3s;
        }

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

        html {
            scroll-behavior: smooth;
            background-color: var(--bg-color);
        }

        body {
            font-family: var(--font-sans);
            color: var(--text-primary);
            line-height: 1.6;
            background-color: var(--bg-color);
            -webkit-font-smoothing: antialiased;
        }

        a {
            color: var(--text-primary);
            text-decoration: none;
            transition: opacity var(--transition-speed);
        }

        a:hover {
            opacity: 0.8;
        }

        ul {
            list-style: none;
        }

        /* Standard Container Layout */
        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }

        /* Header Navigation */
        header {
            background-color: rgba(255, 255, 255, 0.95);
            border-bottom: 2px solid var(--border-color);
            position: sticky;
            top: 0;
            z-index: 100;
            backdrop-filter: blur(10px);
        }

        .nav-wrapper {
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 70px;
        }

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

        .ai-page-logo {
            height: 38px;
            width: auto;
            filter: grayscale(1);
        }

        .nav-menu {
            display: flex;
            gap: 20px;
        }

        .nav-menu a {
            font-size: 14px;
            font-weight: 500;
            text-transform: uppercase;
            padding: 6px 12px;
            border-bottom: 2px solid transparent;
            transition: all var(--transition-speed);
        }

        .nav-menu a:hover {
            border-color: var(--border-color);
            background-color: var(--hover-bg);
        }

        .nav-toggle {
            display: none;
            background: none;
            border: none;
            cursor: pointer;
            padding: 8px;
        }

        .nav-toggle span {
            display: block;
            width: 25px;
            height: 2px;
            background-color: var(--text-primary);
            margin: 5px 0;
            transition: var(--transition-speed);
        }

        /* Hero Section (No image) */
        .hero {
            background-color: #ffffff;
            border-bottom: 2px solid var(--border-color);
            padding: 100px 0 80px 0;
            text-align: center;
            position: relative;
            overflow: hidden;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: radial-gradient(circle, #f0f0f0 10%, transparent 10.01%);
            background-size: 20px 20px;
            opacity: 0.15;
            z-index: 1;
        }

        .hero-content {
            position: relative;
            z-index: 2;
            max-width: 900px;
            margin: 0 auto;
        }

        .hero-tag {
            display: inline-block;
            border: 1px solid var(--border-color);
            padding: 4px 12px;
            font-size: 12px;
            text-transform: uppercase;
            letter-spacing: 2px;
            margin-bottom: 24px;
            background-color: #fff;
        }

        .hero-title {
            font-family: var(--font-serif);
            font-size: 3rem;
            line-height: 1.2;
            font-weight: 800;
            margin-bottom: 24px;
            letter-spacing: -1px;
        }

        .hero-subtitle {
            font-size: 1.15rem;
            color: var(--text-secondary);
            margin-bottom: 40px;
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }

        .hero-cta {
            display: flex;
            justify-content: center;
            gap: 16px;
            flex-wrap: wrap;
        }

        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 12px 28px;
            font-size: 14px;
            font-weight: 600;
            letter-spacing: 1px;
            transition: all var(--transition-speed);
            cursor: pointer;
            border: 2px solid var(--border-color);
        }

        .btn-black {
            background-color: var(--accent-color);
            color: #ffffff;
        }

        .btn-black:hover {
            background-color: #ffffff;
            color: var(--accent-color);
            box-shadow: 4px 4px 0px var(--border-color);
        }

        .btn-outline {
            background-color: transparent;
            color: var(--text-primary);
        }

        .btn-outline:hover {
            background-color: var(--accent-color);
            color: #ffffff;
            box-shadow: 4px 4px 0px var(--border-color);
        }

        /* Section Global Rules */
        section {
            padding: 80px 0;
            border-bottom: 1px solid var(--border-light);
            background-color: var(--container-bg);
        }

        .section-header {
            text-align: center;
            margin-bottom: 60px;
        }

        .section-num {
            font-family: var(--font-serif);
            font-size: 18px;
            color: var(--text-secondary);
            display: block;
            margin-bottom: 8px;
        }

        .section-title {
            font-family: var(--font-serif);
            font-size: 2.2rem;
            font-weight: 700;
            margin-bottom: 16px;
            letter-spacing: -0.5px;
        }

        .section-desc {
            font-size: 1rem;
            color: var(--text-secondary);
            max-width: 600px;
            margin: 0 auto;
        }

        /* Metric Grid */
        .metric-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
            margin-top: 40px;
        }

        .metric-card {
            border: 1px solid var(--border-color);
            padding: 32px 24px;
            text-align: center;
            background: #fff;
            transition: transform var(--transition-speed), box-shadow var(--transition-speed);
        }

        .metric-card:hover {
            transform: translateY(-4px);
            box-shadow: 6px 6px 0px var(--border-color);
        }

        .metric-value {
            font-family: var(--font-serif);
            font-size: 2.5rem;
            font-weight: 800;
            display: block;
            margin-bottom: 8px;
        }

        .metric-label {
            font-size: 14px;
            color: var(--text-secondary);
        }

        /* Service Cards */
        .card-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 30px;
        }

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

        .card {
            border: 1px solid var(--border-color);
            padding: 30px;
            background: #ffffff;
            transition: transform var(--transition-speed);
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .card:hover {
            transform: translateY(-4px);
            box-shadow: 4px 4px 0px var(--border-color);
        }

        .card-title {
            font-size: 1.25rem;
            margin-bottom: 12px;
            font-weight: 700;
        }

        .card-body {
            font-size: 14px;
            color: var(--text-secondary);
            margin-bottom: 20px;
        }

        /* Steps Layout */
        .steps-container {
            position: relative;
            display: flex;
            flex-direction: column;
            gap: 40px;
            max-width: 800px;
            margin: 0 auto;
        }

        .step-item {
            display: flex;
            gap: 30px;
            border-left: 2px solid var(--border-color);
            padding-left: 30px;
            position: relative;
        }

        .step-item::before {
            content: '';
            position: absolute;
            left: -7px;
            top: 0;
            width: 12px;
            height: 12px;
            background-color: var(--accent-color);
            border-radius: 50%;
        }

        .step-num {
            font-family: var(--font-serif);
            font-size: 1.5rem;
            font-weight: 700;
            line-height: 1;
        }

        .step-content h4 {
            font-size: 1.15rem;
            margin-bottom: 8px;
        }

        /* Table Style */
        .table-responsive {
            width: 100%;
            overflow-x: auto;
            margin-top: 20px;
            border: 1px solid var(--border-color);
        }

        table {
            width: 100%;
            border-collapse: collapse;
            text-align: left;
            font-size: 14px;
        }

        th, td {
            padding: 16px 24px;
            border-bottom: 1px solid var(--border-light);
        }

        th {
            background-color: var(--accent-color);
            color: #ffffff;
            font-weight: 600;
        }

        tr:nth-child(even) {
            background-color: #fafafa;
        }

        .tag {
            display: inline-block;
            padding: 2px 8px;
            font-size: 11px;
            border: 1px solid var(--border-color);
            background-color: #fff;
            margin-right: 4px;
            margin-bottom: 4px;
        }

        .tag-dark {
            background-color: var(--accent-color);
            color: #fff;
        }

        /* Form styling */
        .form-box {
            max-width: 650px;
            margin: 0 auto;
            border: 1px solid var(--border-color);
            padding: 40px;
            background: #ffffff;
            box-shadow: 8px 8px 0px var(--border-color);
        }

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

        .form-group label {
            display: block;
            font-size: 13px;
            font-weight: 600;
            margin-bottom: 8px;
            text-transform: uppercase;
        }

        .form-control {
            width: 100%;
            padding: 12px;
            border: 1px solid var(--border-color);
            font-family: inherit;
            font-size: 14px;
            background-color: #fff;
        }

        .form-control:focus {
            outline: none;
            box-shadow: 0 0 0 2px rgba(0,0,0,0.1);
        }

        /* FAQ Accordion */
        .faq-accordion {
            max-width: 800px;
            margin: 0 auto;
        }

        .faq-item {
            border: 1px solid var(--border-color);
            margin-bottom: 12px;
            background: #fff;
        }

        .faq-question {
            padding: 20px;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 600;
            user-select: none;
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height var(--transition-speed) ease-out;
            border-top: 1px solid transparent;
        }

        .faq-answer-inner {
            padding: 20px;
            font-size: 14px;
            color: var(--text-secondary);
        }

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

        .faq-icon::before {
            content: '+';
            font-size: 20px;
            font-weight: bold;
        }

        .faq-item.active .faq-icon::before {
            content: '−';
        }

        /* Reviews Grid */
        .reviews-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 30px;
        }

        .review-card {
            border: 1px solid var(--border-color);
            padding: 30px;
            background: #fff;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
        }

        .review-text {
            font-style: italic;
            font-size: 14px;
            color: var(--text-secondary);
            margin-bottom: 24px;
            line-height: 1.6;
        }

        .review-author {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .review-info h5 {
            font-size: 14px;
            font-weight: 700;
        }

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

        /* Footer & Links */
        footer {
            background-color: var(--accent-color);
            color: #ffffff;
            padding: 60px 0 30px 0;
            font-size: 13px;
        }

        footer a {
            color: #cccccc;
        }

        footer a:hover {
            color: #ffffff;
        }

        .footer-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 40px;
            margin-bottom: 40px;
            border-bottom: 1px solid #333333;
            padding-bottom: 40px;
        }

        .footer-column h5 {
            font-size: 14px;
            margin-bottom: 20px;
            text-transform: uppercase;
            letter-spacing: 1px;
            color: #fff;
        }

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

        .footer-bottom {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 20px;
            color: #888888;
        }

        .friendship-links {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
            margin-top: 15px;
        }

        .friendship-links a {
            font-size: 12px;
            color: #888888;
            border: 1px solid #444;
            padding: 2px 8px;
            border-radius: 2px;
        }

        .friendship-links a:hover {
            color: #ffffff;
            border-color: #ffffff;
        }

        /* Floater Support widget */
        .floater {
            position: fixed;
            bottom: 30px;
            right: 30px;
            z-index: 99;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .floater-btn {
            width: 50px;
            height: 50px;
            background-color: var(--accent-color);
            color: #ffffff;
            border: 1px solid var(--border-color);
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            box-shadow: 4px 4px 0px rgba(0,0,0,0.15);
            transition: transform var(--transition-speed);
        }

        .floater-btn:hover {
            transform: scale(1.05);
        }

        .qr-popover {
            display: none;
            position: absolute;
            bottom: 60px;
            right: 0;
            background-color: white;
            border: 2px solid var(--border-color);
            padding: 16px;
            width: 180px;
            box-shadow: 6px 6px 0px rgba(0,0,0,0.25);
            text-align: center;
        }

        .qr-popover img {
            width: 100%;
            height: auto;
        }

        .qr-popover p {
            color: var(--text-primary);
            font-size: 12px;
            margin-top: 8px;
        }

        /* Banner Grid and Case styling */
        .case-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 30px;
        }

        .case-card {
            border: 1px solid var(--border-color);
            background-color: #fff;
        }

        .case-image-wrapper {
            position: relative;
            aspect-ratio: 16/10;
            overflow: hidden;
            border-bottom: 1px solid var(--border-color);
            background-color: #f0f0f0;
        }

        .case-image-wrapper img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            filter: grayscale(1);
            transition: filter var(--transition-speed);
        }

        .case-image-wrapper:hover img {
            filter: grayscale(0);
        }

        .case-content {
            padding: 20px;
        }

        /* Terms / Glossary Grid */
        .glossary-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
        }

        .glossary-item {
            border-bottom: 1px solid var(--border-color);
            padding-bottom: 16px;
        }

        .glossary-item h5 {
            font-weight: 700;
            margin-bottom: 6px;
        }

        .glossary-item p {
            font-size: 13px;
            color: var(--text-secondary);
        }

        /* Rating / Evaluation section special styles */
        .rating-badge {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 20px;
            margin-bottom: 30px;
        }

        .rating-stars {
            font-size: 24px;
            color: #000;
        }

        .rating-score {
            font-family: var(--font-serif);
            font-size: 4rem;
            font-weight: 800;
            line-height: 1;
        }

        /* Responsive Breakpoints */
        @media (max-width: 1024px) {
            .card-grid, .reviews-grid, .case-grid, .glossary-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .card-grid-4 {
                grid-template-columns: repeat(2, 1fr);
            }
            .metric-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .footer-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 768px) {
            .nav-menu {
                display: none;
                flex-direction: column;
                position: absolute;
                top: 70px;
                left: 0;
                width: 100%;
                background-color: white;
                border-bottom: 2px solid var(--border-color);
                padding: 20px;
                gap: 15px;
            }

            .nav-menu.active {
                display: flex;
            }

            .nav-toggle {
                display: block;
            }

            .hero-title {
                font-size: 2rem;
            }

            .hero-subtitle {
                font-size: 1rem;
            }

            .card-grid, .card-grid-4, .reviews-grid, .case-grid, .glossary-grid, .metric-grid, .footer-grid {
                grid-template-columns: 1fr;
            }

            .rating-badge {
                flex-direction: column;
                gap: 10px;
            }
        }