/* roulang page: index */
:root {
            --primary: #6C3CFA;
            --primary-dark: #5A2ED9;
            --primary-light: rgba(108, 60, 250, 0.1);
            --primary-glow: rgba(108, 60, 250, 0.3);
            --secondary-dark: #1A1A2E;
            --accent: #00F0FF;
            --accent-light: rgba(0, 240, 255, 0.1);
            --bg-light: #F9FAFB;
            --white: #FFFFFF;
            --text-primary: #1A1A2E;
            --text-secondary: #5B5B6C;
            --text-muted: #9E9EAF;
            --border: #E5E7EB;
            --border-light: #F3F4F6;
            --shadow-sm: 0 4px 20px rgba(0, 0, 0, 0.04);
            --shadow-md: 0 8px 30px rgba(108, 60, 250, 0.08);
            --shadow-glow: 0 0 12px rgba(108, 60, 250, 0.3);
            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-full: 20px;
            --transition-fast: 0.25s ease;
            --transition-smooth: 0.3s ease;
            --max-width: 1280px;
            --nav-height: 72px;
        }

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

        body {
            font-family: 'PingFang SC', 'Microsoft YaHei', 'Inter', 'Roboto', sans-serif;
            font-size: 16px;
            line-height: 1.7;
            color: var(--text-primary);
            background-color: var(--bg-light);
            font-weight: 400;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

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

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

        button, input, textarea {
            font-family: inherit;
            font-size: inherit;
            outline: none;
        }

        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }

        /* Header & Navigation */
        .header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            height: var(--nav-height);
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--border);
        }

        .nav {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 100%;
            gap: 32px;
        }

        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 20px;
            font-weight: 700;
            color: var(--text-primary);
            white-space: nowrap;
        }

        .logo-icon {
            width: 32px;
            height: 32px;
            position: relative;
        }

        .logo-icon svg {
            width: 100%;
            height: 100%;
        }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 8px;
            flex-wrap: wrap;
            justify-content: center;
        }

        .nav-chip {
            padding: 6px 16px;
            border-radius: var(--radius-full);
            font-size: 14px;
            font-weight: 500;
            color: var(--text-secondary);
            background: transparent;
            transition: all var(--transition-fast);
            white-space: nowrap;
        }

        .nav-chip:hover {
            background: var(--primary-light);
            color: var(--primary);
        }

        .nav-chip.active {
            background: var(--primary);
            color: var(--white);
        }

        .nav-cta {
            padding: 10px 24px;
            background: var(--primary);
            color: var(--white);
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 15px;
            transition: all var(--transition-fast);
            white-space: nowrap;
        }

        .nav-cta:hover {
            background: var(--primary-dark);
            box-shadow: var(--shadow-glow);
        }

        .menu-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 24px;
            color: var(--text-primary);
            cursor: pointer;
            padding: 8px;
        }

        /* Mobile nav */
        @media (max-width: 768px) {
            .nav-links {
                position: fixed;
                top: var(--nav-height);
                left: 0;
                right: 0;
                background: var(--white);
                flex-direction: column;
                padding: 24px;
                gap: 12px;
                border-bottom: 1px solid var(--border);
                transform: translateY(-120%);
                transition: transform var(--transition-smooth);
                z-index: 999;
                box-shadow: var(--shadow-sm);
            }

            .nav-links.open {
                transform: translateY(0);
            }

            .nav-chip {
                width: 100%;
                text-align: center;
                padding: 12px;
                font-size: 16px;
            }

            .menu-toggle {
                display: block;
            }

            .nav-cta {
                display: none;
            }

            .nav-mobile-cta {
                display: block;
                width: 100%;
                text-align: center;
                padding: 14px;
                background: var(--primary);
                color: var(--white);
                border-radius: var(--radius-sm);
                font-weight: 600;
                margin-top: 8px;
            }
        }

        @media (min-width: 769px) {
            .nav-mobile-cta {
                display: none;
            }
        }

        /* Sections */
        .section {
            padding: 100px 0;
        }

        @media (max-width: 768px) {
            .section {
                padding: 60px 0;
            }
        }

        /* Hero */
        .hero {
            margin-top: var(--nav-height);
            background: var(--white);
            position: relative;
            overflow: hidden;
        }

        .hero-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 60px;
            align-items: center;
            min-height: 600px;
        }

        .hero-left {
            display: flex;
            flex-direction: column;
            gap: 28px;
        }

        .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: var(--primary-light);
            color: var(--primary);
            padding: 8px 18px;
            border-radius: var(--radius-full);
            font-size: 14px;
            font-weight: 600;
            width: fit-content;
        }

        .hero-title {
            font-size: 48px;
            font-weight: 700;
            line-height: 1.2;
            color: var(--text-primary);
            letter-spacing: -0.5px;
        }

        .hero-subtitle {
            font-size: 18px;
            color: var(--text-secondary);
            line-height: 1.7;
            max-width: 500px;
        }

        .hero-btns {
            display: flex;
            gap: 16px;
            flex-wrap: wrap;
        }

        .btn-primary {
            padding: 12px 28px;
            background: var(--primary);
            color: var(--white);
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 16px;
            border: none;
            cursor: pointer;
            transition: all var(--transition-fast);
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }

        .btn-primary:hover {
            background: var(--primary-dark);
            box-shadow: var(--shadow-glow);
        }

        .btn-outline {
            padding: 12px 28px;
            background: transparent;
            color: var(--primary);
            border: 1.5px solid var(--primary);
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 16px;
            cursor: pointer;
            transition: all var(--transition-fast);
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }

        .btn-outline:hover {
            background: var(--primary-light);
        }

        .hero-right {
            position: relative;
            border-radius: var(--radius-md);
            overflow: hidden;
            height: 450px;
            background: linear-gradient(135deg, rgba(108, 60, 250, 0.12), rgba(0, 240, 255, 0.08));
        }

        .hero-right img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            border-radius: var(--radius-md);
        }

        .particles {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            pointer-events: none;
        }

        .particle {
            position: absolute;
            width: 6px;
            height: 6px;
            background: var(--accent);
            border-radius: 50%;
            opacity: 0.4;
            animation: float 3s infinite ease-in-out;
        }

        .particle:nth-child(1) { top: 15%; left: 20%; animation-delay: 0s; }
        .particle:nth-child(2) { top: 60%; left: 75%; animation-delay: 0.7s; width: 8px; height: 8px; }
        .particle:nth-child(3) { top: 35%; left: 50%; animation-delay: 1.4s; width: 4px; height: 4px; }
        .particle:nth-child(4) { top: 80%; left: 30%; animation-delay: 2.1s; }
        .particle:nth-child(5) { top: 10%; left: 80%; animation-delay: 0.3s; width: 5px; height: 5px; }

        @keyframes float {
            0%, 100% { transform: translateY(0) scale(1); opacity: 0.4; }
            50% { transform: translateY(-25px) scale(1.1); opacity: 0.7; }
        }

        .scroll-indicator {
            display: flex;
            justify-content: center;
            padding: 20px 0;
            color: var(--text-muted);
            font-size: 14px;
            gap: 8px;
            align-items: center;
        }

        .scroll-line {
            width: 1px;
            height: 40px;
            background: linear-gradient(to bottom, var(--primary), transparent);
            animation: pulse 2s infinite;
        }

        @keyframes pulse {
            0%, 100% { opacity: 0.3; transform: scaleY(1); }
            50% { opacity: 1; transform: scaleY(1.2); }
        }

        @media (max-width: 768px) {
            .hero-grid {
                grid-template-columns: 1fr;
                gap: 40px;
            }

            .hero-right {
                order: -1;
                height: 300px;
            }

            .hero-title {
                font-size: 32px;
            }

            .hero-subtitle {
                font-size: 16px;
            }
        }

        /* Highlights */
        .highlights {
            background: var(--bg-light);
        }

        .section-header {
            text-align: center;
            margin-bottom: 56px;
        }

        .section-label {
            font-size: 14px;
            font-weight: 600;
            color: var(--primary);
            text-transform: uppercase;
            letter-spacing: 1px;
            margin-bottom: 12px;
        }

        .section-title {
            font-size: 36px;
            font-weight: 600;
            line-height: 1.3;
            color: var(--text-primary);
            margin-bottom: 16px;
        }

        .section-desc {
            font-size: 17px;
            color: var(--text-secondary);
            max-width: 600px;
            margin: 0 auto;
        }

        .highlights-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 28px;
            max-width: 1000px;
            margin: 0 auto;
        }

        .highlight-card {
            background: var(--white);
            border-radius: var(--radius-md);
            padding: 32px;
            box-shadow: var(--shadow-sm);
            transition: all var(--transition-fast);
            border: 1px solid transparent;
        }

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

        .highlight-card.featured {
            grid-column: span 1;
        }

        .highlight-card:nth-child(1) { grid-row: 1; grid-column: 1 / 3; max-width: 480px; }
        .highlight-card:nth-child(2) { grid-row: 1; grid-column: 2 / 4; max-width: 480px; justify-self: end; }
        .highlight-card:nth-child(3) { grid-row: 2; grid-column: 1 / 2; }
        .highlight-card:nth-child(4) { grid-row: 2; grid-column: 2 / 3; }

        .highlight-icon {
            width: 48px;
            height: 48px;
            color: var(--accent);
            margin-bottom: 20px;
        }

        .highlight-title {
            font-size: 20px;
            font-weight: 600;
            margin-bottom: 10px;
            color: var(--text-primary);
        }

        .highlight-text {
            font-size: 15px;
            color: var(--text-secondary);
            line-height: 1.7;
        }

        @media (max-width: 768px) {
            .highlights-grid {
                grid-template-columns: 1fr;
            }
            .highlight-card:nth-child(1),
            .highlight-card:nth-child(2),
            .highlight-card:nth-child(3),
            .highlight-card:nth-child(4) {
                grid-column: auto;
                max-width: 100%;
                justify-self: auto;
            }
            .section-title {
                font-size: 26px;
            }
        }

        /* Cases */
        .cases {
            background: var(--white);
        }

        .case-list {
            display: flex;
            flex-direction: column;
            gap: 40px;
        }

        .case-card {
            display: grid;
            grid-template-columns: 45% 55%;
            gap: 40px;
            align-items: center;
            background: var(--bg-light);
            border-radius: var(--radius-md);
            overflow: hidden;
            box-shadow: var(--shadow-sm);
            transition: all var(--transition-fast);
        }

        .case-card:hover {
            box-shadow: var(--shadow-md);
            transform: translateY(-2px);
        }

        .case-card.reverse {
            grid-template-columns: 55% 45%;
        }

        .case-card.reverse .case-img {
            order: 2;
        }

        .case-card.reverse .case-content {
            order: 1;
        }

        .case-img {
            height: 100%;
            min-height: 320px;
        }

        .case-img img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            border-radius: var(--radius-sm);
        }

        .case-content {
            padding: 32px;
            display: flex;
            flex-direction: column;
            gap: 16px;
        }

        .case-tags {
            display: flex;
            gap: 8px;
            flex-wrap: wrap;
        }

        .case-tag {
            padding: 4px 12px;
            background: var(--border-light);
            border-radius: var(--radius-full);
            font-size: 13px;
            color: var(--text-secondary);
            font-weight: 500;
        }

        .case-title {
            font-size: 22px;
            font-weight: 600;
            color: var(--text-primary);
            line-height: 1.4;
        }

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

        .case-stats {
            display: flex;
            gap: 32px;
        }

        .stat-item {
            display: flex;
            flex-direction: column;
        }

        .stat-num {
            font-size: 32px;
            font-weight: 700;
            color: var(--primary);
            line-height: 1;
        }

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

        @media (max-width: 768px) {
            .case-card,
            .case-card.reverse {
                grid-template-columns: 1fr;
            }
            .case-card.reverse .case-img {
                order: -1;
            }
            .case-card.reverse .case-content {
                order: 2;
            }
            .case-img {
                min-height: 240px;
            }
        }

        /* Compare */
        .compare {
            background: var(--bg-light);
        }

        .compare-wrapper {
            display: grid;
            grid-template-columns: 1fr auto 1fr;
            gap: 24px;
            align-items: start;
            max-width: 900px;
            margin: 0 auto;
        }

        .compare-col {
            background: var(--white);
            border-radius: var(--radius-md);
            padding: 36px;
            box-shadow: var(--shadow-sm);
        }

        .compare-col.recommended {
            background: #F8F6FF;
            border: 1px solid var(--primary-light);
            position: relative;
        }

        .compare-col-title {
            font-size: 22px;
            font-weight: 600;
            margin-bottom: 28px;
            color: var(--text-primary);
        }

        .compare-item {
            display: flex;
            align-items: center;
            gap: 14px;
            padding: 12px 0;
            border-bottom: 1px solid var(--border-light);
            min-height: 48px;
        }

        .compare-icon {
            width: 24px;
            height: 24px;
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
        }

        .icon-check {
            color: #10B981;
            background: rgba(16, 185, 129, 0.1);
            border-radius: 50%;
            padding: 4px;
        }

        .icon-cross {
            color: #EF4444;
            background: rgba(239, 68, 68, 0.08);
            border-radius: 50%;
            padding: 4px;
        }

        .compare-text {
            font-size: 15px;
            color: var(--text-primary);
        }

        .vs-badge {
            width: 48px;
            height: 48px;
            background: var(--white);
            border: 2px solid var(--primary);
            color: var(--primary);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            font-size: 14px;
            margin-top: 40px;
        }

        @media (max-width: 768px) {
            .compare-wrapper {
                grid-template-columns: 1fr;
            }
            .vs-badge {
                margin: 0 auto;
                transform: rotate(90deg);
            }
        }

        /* FAQ */
        .faq {
            background: var(--white);
        }

        .faq-list {
            max-width: 780px;
            margin: 0 auto;
        }

        .faq-item {
            border-bottom: 1px solid var(--border);
            overflow: hidden;
        }

        .faq-question {
            padding: 20px 0;
            font-size: 18px;
            font-weight: 500;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            color: var(--text-primary);
            transition: color var(--transition-fast);
            position: relative;
            padding-left: 16px;
        }

        .faq-question::before {
            content: '';
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
            width: 3px;
            height: 0;
            background: var(--primary);
            border-radius: 2px;
            transition: height var(--transition-smooth);
        }

        .faq-item.open .faq-question::before {
            height: 24px;
        }

        .faq-question i {
            transition: transform var(--transition-smooth);
            color: var(--text-muted);
            font-size: 16px;
        }

        .faq-item.open .faq-question i {
            transform: rotate(180deg);
            color: var(--primary);
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease, padding 0.3s ease;
            font-size: 15px;
            color: var(--text-secondary);
            line-height: 1.7;
        }

        .faq-item.open .faq-answer {
            max-height: 300px;
            padding: 0 0 20px 16px;
        }

        /* Contact CTA */
        .contact-cta {
            background: var(--secondary-dark);
            color: var(--white);
            position: relative;
            overflow: hidden;
        }

        .contact-cta::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle at 30% 40%, rgba(108, 60, 250, 0.08) 0%, transparent 50%);
            pointer-events: none;
        }

        .contact-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 60px;
            align-items: center;
            position: relative;
            z-index: 1;
        }

        .contact-info h3 {
            font-size: 28px;
            font-weight: 600;
            margin-bottom: 16px;
            color: var(--white);
        }

        .contact-info p {
            color: #9E9EAF;
            font-size: 16px;
            margin-bottom: 28px;
        }

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

        .contact-detail-item {
            display: flex;
            align-items: center;
            gap: 12px;
            color: #9E9EAF;
            font-size: 15px;
        }

        .contact-detail-item i {
            color: var(--accent);
            width: 20px;
        }

        .contact-form {
            background: rgba(255, 255, 255, 0.05);
            border-radius: var(--radius-md);
            padding: 32px;
            backdrop-filter: blur(8px);
            border: 1px solid rgba(255, 255, 255, 0.08);
        }

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

        .form-group label {
            display: block;
            margin-bottom: 8px;
            font-size: 14px;
            font-weight: 500;
            color: #9E9EAF;
        }

        .form-input {
            width: 100%;
            height: 48px;
            padding: 0 16px;
            border-radius: var(--radius-sm);
            border: 1px solid rgba(255, 255, 255, 0.15);
            background: rgba(255, 255, 255, 0.05);
            color: var(--white);
            font-size: 15px;
            transition: all var(--transition-fast);
        }

        .form-input:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(108, 60, 250, 0.15);
        }

        textarea.form-input {
            height: 100px;
            padding: 14px 16px;
            resize: vertical;
        }

        .form-submit {
            width: 100%;
            padding: 14px;
            background: var(--primary);
            color: var(--white);
            border: none;
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 16px;
            cursor: pointer;
            transition: all var(--transition-fast);
        }

        .form-submit:hover {
            background: var(--primary-dark);
            box-shadow: var(--shadow-glow);
        }

        @media (max-width: 768px) {
            .contact-grid {
                grid-template-columns: 1fr;
            }
        }

        /* Footer */
        .footer {
            background: var(--secondary-dark);
            padding: 60px 0 30px;
            color: #9E9EAF;
        }

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

        .footer-col h4 {
            color: var(--white);
            font-size: 16px;
            font-weight: 600;
            margin-bottom: 20px;
        }

        .footer-col p, .footer-col a {
            font-size: 14px;
            color: #9E9EAF;
            line-height: 2;
            transition: color var(--transition-fast);
            display: block;
        }

        .footer-col a:hover {
            color: var(--accent);
        }

        .social-links {
            display: flex;
            gap: 16px;
            margin-top: 16px;
        }

        .social-links a {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.08);
            display: flex;
            align-items: center;
            justify-content: center;
            color: #9E9EAF;
            font-size: 16px;
            transition: all var(--transition-fast);
        }

        .social-links a:hover {
            background: var(--primary);
            color: var(--white);
        }

        .copyright {
            text-align: center;
            font-size: 13px;
            color: #5B5B6C;
            padding-top: 24px;
            border-top: 1px solid rgba(255, 255, 255, 0.06);
        }

        @media (max-width: 768px) {
            .footer-grid {
                grid-template-columns: 1fr 1fr;
            }
        }

        @media (max-width: 520px) {
            .footer-grid {
                grid-template-columns: 1fr;
            }
        }

        /* Scroll reveal */
        .reveal {
            opacity: 0;
            transform: translateY(24px);
            transition: opacity 0.5s ease, transform 0.5s ease;
        }

        .reveal.visible {
            opacity: 1;
            transform: translateY(0);
        }

        /* Decor */
        .decor-lines {
            position: absolute;
            pointer-events: none;
            opacity: 0.08;
        }

        .decor-line {
            stroke: var(--accent);
            fill: none;
            stroke-width: 1;
        }