/* roulang page: index */
:root {
            --bg-primary: #0a0a0f;
            --bg-secondary: #111118;
            --bg-card: #14141a;
            --bg-footer: #08080d;
            --text-primary: #f0efe8;
            --text-secondary: #9a9aa3;
            --accent: #c8a44e;
            --accent-hover: #d9b96a;
            --accent-glow: rgba(200, 164, 78, 0.08);
            --accent-border: rgba(200, 164, 78, 0.35);
            --neon-cyan: #3df0c8;
            --border-subtle: #1e1e28;
            --border-dim: rgba(255, 255, 255, 0.06);
            --border-nav: rgba(255, 255, 255, 0.08);
            --overlay-hero: rgba(10, 10, 15, 0.75);
            --radius-sm: 4px;
            --radius-md: 6px;
            --radius-lg: 14px;
            --radius-xl: 16px;
            --font-stack: 'PingFang SC', 'Noto Sans SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
            --max-width: 1200px;
            --nav-height: 68px;
            --nav-height-mobile: 58px;
            --section-gap: 120px;
            --section-gap-mobile: 70px;
            --card-pad: 36px;
            --card-pad-mobile: 22px;
            --transition-fast: 0.2s ease;
            --transition-normal: 0.25s ease;
            --transition-slow: 0.3s ease;
            --transition-reveal: 0.6s ease;
        }

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

        html {
            scroll-behavior: smooth;
            scroll-padding-top: var(--nav-height);
            font-size: 16px;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        body {
            font-family: var(--font-stack);
            background-color: var(--bg-primary);
            color: var(--text-primary);
            line-height: 1.7;
            overflow-x: hidden;
            min-height: 100vh;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: color var(--transition-fast);
        }
        button {
            font-family: inherit;
            cursor: pointer;
            border: none;
            background: none;
            font-size: inherit;
            color: inherit;
        }
        input {
            font-family: inherit;
        }
        ul {
            list-style: none;
        }

        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 28px;
        }

        /* ============ NAVIGATION ============ */
        .nav {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            height: var(--nav-height);
            display: flex;
            align-items: center;
            transition: background-color var(--transition-slow), box-shadow var(--transition-slow);
            background-color: transparent;
        }
        .nav.scrolled {
            background-color: rgba(10, 10, 15, 0.96);
            box-shadow: 0 1px 0 var(--border-nav);
        }
        .nav-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 28px;
            height: 100%;
        }
        .nav-logo {
            font-size: 1.3rem;
            font-weight: 700;
            color: var(--text-primary);
            letter-spacing: 0.04em;
            white-space: nowrap;
            flex-shrink: 0;
        }
        .nav-logo .logo-accent {
            color: var(--accent);
        }
        .nav-links {
            display: flex;
            align-items: center;
            gap: 30px;
        }
        .nav-links a {
            font-size: 0.92rem;
            font-weight: 500;
            color: var(--text-secondary);
            transition: color var(--transition-fast);
            white-space: nowrap;
        }
        .nav-links a:hover {
            color: var(--text-primary);
        }
        .nav-cta-btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: var(--accent);
            color: #0a0a0f !important;
            font-weight: 600;
            padding: 9px 20px;
            border-radius: var(--radius-md);
            font-size: 0.9rem !important;
            letter-spacing: 0.02em;
            transition: background var(--transition-normal), transform var(--transition-normal);
            white-space: nowrap;
        }
        .nav-cta-btn:hover {
            background: var(--accent-hover);
            transform: scale(1.03);
            color: #0a0a0f !important;
        }
        .nav-cta-btn:active {
            transform: scale(0.98);
        }

        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            padding: 6px;
            z-index: 1001;
            background: none;
            border: none;
        }
        .hamburger span {
            display: block;
            width: 24px;
            height: 2px;
            background: var(--text-primary);
            border-radius: 2px;
            transition: transform var(--transition-normal), opacity var(--transition-normal);
        }
        .hamburger.active span:nth-child(1) {
            transform: rotate(45deg) translate(5px, 5px);
        }
        .hamburger.active span:nth-child(2) {
            opacity: 0;
        }
        .hamburger.active span:nth-child(3) {
            transform: rotate(-45deg) translate(5px, -5px);
        }
        .mobile-menu {
            display: none;
            position: fixed;
            inset: 0;
            background: rgba(10, 10, 15, 0.97);
            z-index: 999;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 28px;
        }
        .mobile-menu.active {
            display: flex;
        }
        .mobile-menu a {
            font-size: 1.3rem;
            font-weight: 500;
            color: var(--text-primary);
            letter-spacing: 0.03em;
        }
        .mobile-menu .nav-cta-btn {
            font-size: 1.05rem !important;
            padding: 12px 28px;
            margin-top: 8px;
        }

        /* ============ HERO ============ */
        .hero {
            position: relative;
            min-height: 92vh;
            display: flex;
            align-items: center;
            justify-content: center;
            background-image: url('/assets/images/backpic/back-1.webp');
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
            overflow: hidden;
        }
        .hero::before {
            content: '';
            position: absolute;
            inset: 0;
            background: var(--overlay-hero);
            z-index: 1;
        }
        .hero-content {
            position: relative;
            z-index: 2;
            text-align: left;
            max-width: 780px;
            width: 100%;
            padding: 0 28px;
            margin-top: var(--nav-height);
        }
        .hero-badge {
            display: inline-block;
            font-size: 0.82rem;
            font-weight: 500;
            letter-spacing: 0.06em;
            color: var(--accent);
            border: 1px solid rgba(200, 164, 78, 0.4);
            padding: 6px 16px;
            border-radius: 20px;
            margin-bottom: 24px;
            opacity: 0;
            transform: translateY(20px);
            animation: fadeUp 0.6s ease forwards;
        }
        .hero h1 {
            font-size: clamp(2.4rem, 5vw, 4.2rem);
            font-weight: 800;
            line-height: 1.12;
            letter-spacing: -0.02em;
            color: var(--text-primary);
            margin-bottom: 20px;
            opacity: 0;
            transform: translateY(20px);
            animation: fadeUp 0.6s ease 0.12s forwards;
        }
        .hero h1 .highlight {
            color: var(--accent);
        }
        .hero-subtitle {
            font-size: clamp(1rem, 1.8vw, 1.25rem);
            font-weight: 400;
            line-height: 1.6;
            color: var(--text-secondary);
            max-width: 560px;
            margin-bottom: 36px;
            opacity: 0;
            transform: translateY(20px);
            animation: fadeUp 0.6s ease 0.22s forwards;
        }
        .hero-btns {
            display: flex;
            flex-wrap: wrap;
            gap: 14px;
            opacity: 0;
            transform: translateY(20px);
            animation: fadeUp 0.6s ease 0.32s forwards;
        }
        .btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: var(--accent);
            color: #0a0a0f;
            font-weight: 600;
            font-size: 1rem;
            padding: 15px 30px;
            border-radius: var(--radius-md);
            letter-spacing: 0.03em;
            transition: background var(--transition-normal), transform var(--transition-normal), box-shadow var(--transition-normal);
            white-space: nowrap;
        }
        .btn-primary:hover {
            background: var(--accent-hover);
            transform: scale(1.04);
            box-shadow: 0 0 40px var(--accent-glow);
        }
        .btn-primary:active {
            transform: scale(0.97);
        }
        .btn-outline {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: transparent;
            color: var(--text-primary);
            font-weight: 500;
            font-size: 1rem;
            padding: 14px 28px;
            border-radius: var(--radius-md);
            border: 1.5px solid var(--text-secondary);
            letter-spacing: 0.03em;
            transition: border-color var(--transition-normal), background var(--transition-normal), color var(--transition-normal);
            white-space: nowrap;
        }
        .btn-outline:hover {
            border-color: var(--text-primary);
            background: rgba(255, 255, 255, 0.04);
        }
        .hero-scroll-indicator {
            position: absolute;
            bottom: 32px;
            left: 50%;
            transform: translateX(-50%);
            z-index: 2;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 6px;
            color: var(--text-secondary);
            font-size: 0.75rem;
            letter-spacing: 0.05em;
            animation: bounceDown 2s ease-in-out infinite;
        }
        .hero-scroll-indicator .scroll-line {
            width: 1px;
            height: 28px;
            background: var(--text-secondary);
            border-radius: 1px;
        }

        @keyframes fadeUp {
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        @keyframes bounceDown {
            0%,
            100% {
                transform: translateX(-50%) translateY(0);
            }
            50% {
                transform: translateX(-50%) translateY(10px);
            }
        }

        /* ============ SECTIONS ============ */
        .section {
            padding: var(--section-gap) 0;
        }
        .section-alt {
            background-color: var(--bg-secondary);
        }
        .section-label {
            display: inline-block;
            font-size: 0.8rem;
            font-weight: 500;
            letter-spacing: 0.08em;
            color: var(--accent);
            text-transform: uppercase;
            margin-bottom: 12px;
        }
        .section h2 {
            font-size: clamp(1.8rem, 3.5vw, 2.6rem);
            font-weight: 700;
            line-height: 1.22;
            letter-spacing: -0.01em;
            color: var(--text-primary);
            margin-bottom: 16px;
        }
        .section-intro {
            color: var(--text-secondary);
            font-size: 1.05rem;
            line-height: 1.6;
            max-width: 600px;
            margin-bottom: 48px;
        }

        /* ============ PAIN POINTS ============ */
        .pain-grid {
            display: grid;
            grid-template-columns: 1.3fr 1fr;
            gap: 24px;
            align-items: stretch;
        }
        .pain-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: var(--card-pad);
            transition: border-color var(--transition-normal), transform var(--transition-normal);
            position: relative;
            overflow: hidden;
        }
        .pain-card:hover {
            border-color: var(--accent-border);
            transform: translateY(-3px);
        }
        .pain-card.large {
            grid-row: span 2;
            display: flex;
            flex-direction: column;
            justify-content: center;
        }
        .pain-card .pain-number {
            font-size: 0.78rem;
            font-weight: 700;
            color: var(--accent);
            letter-spacing: 0.06em;
            margin-bottom: 10px;
        }
        .pain-card h3 {
            font-size: 1.35rem;
            font-weight: 600;
            margin-bottom: 10px;
            color: var(--text-primary);
            line-height: 1.3;
        }
        .pain-card p {
            color: var(--text-secondary);
            font-size: 0.95rem;
            line-height: 1.65;
        }
        .pain-card .pain-icon-placeholder {
            width: 44px;
            height: 44px;
            border-radius: var(--radius-sm);
            background: rgba(200, 164, 78, 0.1);
            border: 1px solid rgba(200, 164, 78, 0.2);
            margin-bottom: 16px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.3rem;
        }

        /* ============ SOLUTIONS ============ */
        .solutions-layout {
            display: grid;
            grid-template-columns: 1.5fr 1fr;
            gap: 24px;
        }
        .solution-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            overflow: hidden;
            transition: border-color var(--transition-normal), transform var(--transition-normal);
            display: flex;
            flex-direction: column;
        }
        .solution-card:hover {
            border-color: var(--accent-border);
            transform: translateY(-3px);
        }
        .solution-card.featured {
            grid-row: span 3;
        }
        .solution-card-img {
            width: 100%;
            height: 200px;
            object-fit: cover;
            display: block;
        }
        .solution-card.featured .solution-card-img {
            height: 280px;
        }
        .solution-card-body {
            padding: var(--card-pad);
            flex: 1;
            display: flex;
            flex-direction: column;
        }
        .solution-card-body h3 {
            font-size: 1.25rem;
            font-weight: 600;
            margin-bottom: 8px;
            color: var(--text-primary);
        }
        .solution-card-body p {
            color: var(--text-secondary);
            font-size: 0.93rem;
            line-height: 1.6;
            flex: 1;
        }
        .solution-tag {
            display: inline-block;
            font-size: 0.75rem;
            font-weight: 500;
            color: var(--accent);
            background: rgba(200, 164, 78, 0.08);
            padding: 4px 10px;
            border-radius: var(--radius-sm);
            margin-top: 14px;
            align-self: flex-start;
            letter-spacing: 0.04em;
        }

        /* ============ RESULTS ============ */
        .results-row {
            display: flex;
            justify-content: space-around;
            gap: 20px;
            flex-wrap: wrap;
            text-align: center;
        }
        .result-item {
            flex: 1;
            min-width: 160px;
            padding: 28px 16px;
        }
        .result-number {
            font-size: clamp(2.4rem, 4.5vw, 3.2rem);
            font-weight: 800;
            color: var(--accent);
            line-height: 1;
            margin-bottom: 8px;
            font-variant-numeric: tabular-nums;
            letter-spacing: -0.01em;
        }
        .result-label {
            font-size: 0.88rem;
            color: var(--text-secondary);
            letter-spacing: 0.03em;
            font-weight: 500;
        }
        .result-divider {
            width: 1px;
            background: var(--border-dim);
            align-self: stretch;
            flex-shrink: 0;
        }

        /* ============ TESTIMONIALS ============ */
        .testimonials-scroll {
            display: flex;
            gap: 24px;
            overflow-x: auto;
            scroll-snap-type: x mandatory;
            -webkit-overflow-scrolling: touch;
            padding-bottom: 12px;
            scrollbar-width: thin;
            scrollbar-color: var(--border-subtle) transparent;
        }
        .testimonials-scroll::-webkit-scrollbar {
            height: 5px;
        }
        .testimonials-scroll::-webkit-scrollbar-track {
            background: transparent;
        }
        .testimonials-scroll::-webkit-scrollbar-thumb {
            background: var(--border-subtle);
            border-radius: 10px;
        }
        .testimonial-card {
            flex: 0 0 390px;
            scroll-snap-align: start;
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: var(--card-pad);
            position: relative;
            transition: border-color var(--transition-normal);
            min-height: 220px;
            display: flex;
            flex-direction: column;
        }
        .testimonial-card:nth-child(2) {
            border-color: var(--accent-border);
            transform: translateY(-6px);
        }
        .testimonial-card:hover {
            border-color: var(--accent-border);
        }
        .testimonial-quote-mark {
            font-size: 5rem;
            line-height: 0.6;
            color: var(--accent);
            opacity: 0.18;
            font-family: Georgia, 'Times New Roman', serif;
            pointer-events: none;
            user-select: none;
            position: absolute;
            top: 14px;
            left: 20px;
        }
        .testimonial-card blockquote {
            font-size: 1.02rem;
            line-height: 1.7;
            color: var(--text-primary);
            flex: 1;
            position: relative;
            z-index: 1;
            font-style: normal;
        }
        .testimonial-author {
            margin-top: 18px;
            padding-top: 16px;
            border-top: 1px solid var(--border-dim);
            display: flex;
            align-items: center;
            gap: 12px;
        }
        .testimonial-avatar {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            object-fit: cover;
            flex-shrink: 0;
            background: var(--border-subtle);
        }
        .testimonial-author strong {
            font-size: 0.95rem;
            color: var(--text-primary);
            display: block;
        }
        .testimonial-author span {
            font-size: 0.8rem;
            color: var(--text-secondary);
        }

        /* ============ FAQ ============ */
        .faq-list {
            display: flex;
            flex-direction: column;
            gap: 0;
            border-top: 1px solid var(--border-dim);
        }
        .faq-item {
            border-bottom: 1px solid var(--border-dim);
        }
        .faq-question {
            width: 100%;
            text-align: left;
            padding: 20px 0;
            font-size: 1.05rem;
            font-weight: 600;
            color: var(--text-primary);
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: 16px;
            background: none;
            border: none;
            cursor: pointer;
            transition: color var(--transition-fast);
            line-height: 1.4;
            letter-spacing: 0.01em;
        }
        .faq-question:hover {
            color: var(--accent);
        }
        .faq-icon {
            flex-shrink: 0;
            width: 22px;
            height: 22px;
            position: relative;
            transition: transform var(--transition-slow);
        }
        .faq-icon::before,
        .faq-icon::after {
            content: '';
            position: absolute;
            background: var(--text-secondary);
            transition: all var(--transition-slow);
            border-radius: 1px;
        }
        .faq-icon::before {
            width: 100%;
            height: 1.5px;
            top: 50%;
            left: 0;
            transform: translateY(-50%);
        }
        .faq-icon::after {
            width: 1.5px;
            height: 100%;
            left: 50%;
            top: 0;
            transform: translateX(-50%);
        }
        .faq-item.open .faq-icon {
            transform: rotate(45deg);
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height var(--transition-slow), padding var(--transition-slow);
            color: var(--text-secondary);
            font-size: 0.95rem;
            line-height: 1.7;
            padding: 0;
        }
        .faq-item.open .faq-answer {
            max-height: 300px;
            padding-bottom: 20px;
        }

        /* ============ CTA ============ */
        .cta-section {
            background: var(--bg-secondary);
            padding: 90px 0;
            text-align: center;
        }
        .cta-section h2 {
            font-size: clamp(1.8rem, 3.2vw, 2.5rem);
            font-weight: 700;
            color: var(--text-primary);
            margin-bottom: 16px;
            letter-spacing: -0.01em;
        }
        .cta-section p {
            color: var(--text-secondary);
            font-size: 1.05rem;
            margin-bottom: 32px;
            max-width: 520px;
            margin-left: auto;
            margin-right: auto;
        }
        .cta-section .btn-primary {
            font-size: 1.05rem;
            padding: 17px 36px;
            border-radius: var(--radius-md);
        }

        /* ============ FOOTER ============ */
        .footer {
            background: var(--bg-footer);
            padding: 60px 0 0;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 1.2fr 1fr 1fr;
            gap: 40px;
            padding-bottom: 40px;
        }
        .footer-brand .nav-logo {
            margin-bottom: 10px;
            display: inline-block;
        }
        .footer-brand p {
            color: var(--text-secondary);
            font-size: 0.9rem;
            line-height: 1.6;
        }
        .footer-links h4 {
            font-size: 0.85rem;
            font-weight: 600;
            letter-spacing: 0.05em;
            color: var(--text-primary);
            margin-bottom: 16px;
            text-transform: uppercase;
        }
        .footer-links a {
            display: block;
            color: var(--text-secondary);
            font-size: 0.9rem;
            margin-bottom: 10px;
            transition: color var(--transition-fast);
        }
        .footer-links a:hover {
            color: var(--text-primary);
        }
        .footer-bottom {
            border-top: 1px solid var(--border-dim);
            padding: 18px 0;
            text-align: center;
            font-size: 0.78rem;
            color: var(--text-secondary);
            letter-spacing: 0.03em;
        }

        /* ============ REVEAL ON SCROLL ============ */
        .reveal {
            opacity: 0;
            transform: translateY(36px);
            transition: opacity var(--transition-reveal), transform var(--transition-reveal);
        }
        .reveal.visible {
            opacity: 1;
            transform: translateY(0);
        }
        .reveal-delay-1 {
            transition-delay: 0.08s;
        }
        .reveal-delay-2 {
            transition-delay: 0.16s;
        }
        .reveal-delay-3 {
            transition-delay: 0.24s;
        }
        .reveal-delay-4 {
            transition-delay: 0.32s;
        }

        /* ============ RESPONSIVE ============ */
        @media (max-width: 1024px) {
            .pain-grid {
                grid-template-columns: 1fr 1fr;
            }
            .pain-card.large {
                grid-row: span 1;
                grid-column: span 2;
            }
            .solutions-layout {
                grid-template-columns: 1fr 1fr;
            }
            .solution-card.featured {
                grid-row: span 2;
                grid-column: span 2;
            }
            .testimonial-card {
                flex: 0 0 340px;
            }
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 32px;
            }
        }

        @media (max-width: 768px) {
            .nav-links {
                display: none;
            }
            .hamburger {
                display: flex;
            }
            .nav-inner {
                padding: 0 20px;
            }
            .container {
                padding: 0 20px;
            }
            .hero-content {
                text-align: left;
                padding: 0 20px;
            }
            .hero h1 {
                font-size: clamp(2rem, 7vw, 2.6rem);
            }
            .hero-subtitle {
                font-size: 1rem;
            }
            .section {
                padding: var(--section-gap-mobile) 0;
            }
            .pain-grid {
                grid-template-columns: 1fr;
            }
            .pain-card.large {
                grid-column: span 1;
            }
            .solutions-layout {
                grid-template-columns: 1fr;
            }
            .solution-card.featured {
                grid-row: span 1;
                grid-column: span 1;
            }
            .solution-card.featured .solution-card-img {
                height: 200px;
            }
            .results-row {
                display: grid;
                grid-template-columns: 1fr 1fr;
                gap: 16px;
            }
            .result-divider {
                display: none;
            }
            .result-item {
                padding: 18px 10px;
            }
            .testimonial-card {
                flex: 0 0 290px;
            }
            .testimonial-card:nth-child(2) {
                transform: none;
            }
            .cta-section {
                padding: 60px 0;
            }
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 28px;
                text-align: center;
            }
            .hero-btns {
                flex-direction: column;
                align-items: flex-start;
            }
            .btn-primary,
            .btn-outline {
                width: 100%;
                justify-content: center;
            }
            .hero-scroll-indicator {
                bottom: 18px;
            }
        }

        @media (max-width: 520px) {
            .nav {
                height: var(--nav-height-mobile);
            }
            html {
                scroll-padding-top: var(--nav-height-mobile);
            }
            .hero {
                min-height: 90vh;
            }
            .hero-content {
                margin-top: var(--nav-height-mobile);
            }
            .hero h1 {
                font-size: 1.9rem;
            }
            .hero-subtitle {
                font-size: 0.9rem;
            }
            .section h2 {
                font-size: 1.5rem;
            }
            .pain-card {
                padding: var(--card-pad-mobile);
            }
            .solution-card-body {
                padding: var(--card-pad-mobile);
            }
            .testimonial-card {
                flex: 0 0 260px;
                padding: var(--card-pad-mobile);
            }
            .results-row {
                grid-template-columns: 1fr 1fr;
                gap: 8px;
            }
            .result-number {
                font-size: 2rem;
            }
            .btn-primary {
                padding: 13px 22px;
                font-size: 0.95rem;
            }
            .btn-outline {
                padding: 12px 20px;
                font-size: 0.95rem;
            }
            .faq-question {
                font-size: 0.95rem;
                padding: 16px 0;
            }
        }