/* roulang page: index */
:root {
            --color-primary: #0A4C7B;
            --color-primary-light: #2D7FA8;
            --color-accent: #D4A017;
            --color-accent-hover: #b8890f;
            --color-bg: #F8FBFE;
            --color-bg-alt: #EEF2F6;
            --color-white: #FFFFFF;
            --color-text: #1A1A1A;
            --color-text-secondary: #4A4A4A;
            --color-cta-green: #0F7B4E;
            --color-cta-green-hover: #0b5e3b;
            --color-deep-panel: #083a5e;
            --radius-card: 12px;
            --radius-btn: 8px;
            --radius-input: 6px;
            --shadow-card: 0 4px 12px rgba(0, 43, 78, 0.08);
            --shadow-card-hover: 0 8px 24px rgba(0, 43, 78, 0.12);
            --shadow-gold-glow: 0 0 18px rgba(212, 160, 23, 0.25);
            --font-cn: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
            --font-en: "Inter", "Segoe UI", Roboto, sans-serif;
            --header-height: 72px;
            --container-max: 1200px;
            --section-gap-desktop: 100px;
            --section-gap-tablet: 80px;
            --section-gap-mobile: 60px;
            --card-padding: 32px;
            --grid-gap: 30px;
        }

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

        html {
            scroll-behavior: smooth;
            scroll-padding-top: var(--header-height);
        }

        body {
            font-family: var(--font-cn);
            font-size: 1rem;
            line-height: 1.7;
            color: var(--color-text);
            background-color: var(--color-bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            overflow-x: hidden;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: color 0.25s ease;
        }
        a:hover {
            color: var(--color-primary-light);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        button,
        input,
        textarea {
            font-family: inherit;
            font-size: inherit;
            outline: none;
            border: none;
        }
        button {
            cursor: pointer;
        }
        ul {
            list-style: none;
        }

        .container {
            max-width: var(--container-max);
            margin: 0 auto;
            padding: 0 20px;
        }

        .section-gap {
            padding: var(--section-gap-desktop) 0;
        }
        @media (max-width: 1024px) {
            .section-gap {
                padding: var(--section-gap-tablet) 0;
            }
        }
        @media (max-width: 768px) {
            .section-gap {
                padding: var(--section-gap-mobile) 0;
            }
        }

        /* ========== HEADER / NAVIGATION ========== */
        .site-header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            height: var(--header-height);
            display: flex;
            align-items: center;
            background: rgba(255, 255, 255, 0.85);
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            transition: background 0.3s ease, box-shadow 0.3s ease;
            border-bottom: 1px solid transparent;
        }
        .site-header.scrolled {
            background: #fff;
            box-shadow: 0 2px 16px rgba(0, 43, 78, 0.08);
            border-bottom: 1px solid #e8edf3;
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
            max-width: var(--container-max);
            margin: 0 auto;
            padding: 0 20px;
        }
        .logo-link {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 1.35rem;
            color: var(--color-primary);
            letter-spacing: 0.5px;
            flex-shrink: 0;
        }
        .logo-link i {
            font-size: 1.5rem;
            color: var(--color-accent);
            transition: transform 0.3s ease;
        }
        .logo-link:hover i {
            transform: rotate(-10deg) scale(1.1);
        }
        .logo-link:hover {
            color: var(--color-primary);
        }
        .nav-list {
            display: flex;
            align-items: center;
            gap: 28px;
        }
        .nav-list a {
            font-size: 0.95rem;
            font-weight: 500;
            color: var(--color-text-secondary);
            padding: 6px 0;
            position: relative;
            transition: color 0.25s ease;
            white-space: nowrap;
        }
        .nav-list a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 2.5px;
            background: var(--color-primary-light);
            border-radius: 2px;
            transition: width 0.3s ease;
        }
        .nav-list a:hover,
        .nav-list a.active {
            color: var(--color-primary);
        }
        .nav-list a:hover::after,
        .nav-list a.active::after {
            width: 100%;
        }
        .hamburger-btn {
            display: none;
            background: none;
            border: none;
            font-size: 1.5rem;
            color: var(--color-primary);
            cursor: pointer;
            width: 40px;
            height: 40px;
            align-items: center;
            justify-content: center;
            border-radius: 8px;
            transition: background 0.25s ease;
        }
        .hamburger-btn:hover {
            background: #eef2f6;
        }
        .mobile-nav-overlay {
            display: none;
            position: fixed;
            top: var(--header-height);
            left: 0;
            right: 0;
            bottom: 0;
            background: #eaf3fa;
            z-index: 999;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 24px;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.3s ease;
        }
        .mobile-nav-overlay.open {
            display: flex;
            opacity: 1;
            pointer-events: auto;
        }
        .mobile-nav-overlay a {
            font-size: 1.3rem;
            font-weight: 600;
            color: var(--color-primary);
            padding: 10px 20px;
            border-radius: 8px;
            transition: background 0.25s ease;
        }
        .mobile-nav-overlay a:hover {
            background: rgba(10, 76, 123, 0.08);
        }

        @media (max-width: 768px) {
            .nav-list {
                display: none;
            }
            .hamburger-btn {
                display: flex;
            }
        }

        /* ========== HERO ========== */
        .hero-section {
            padding-top: calc(var(--header-height) + 40px);
            padding-bottom: 60px;
            background: linear-gradient(180deg, #F8FBFE 0%, #EEF4F9 100%);
            min-height: 90vh;
            display: flex;
            align-items: center;
        }
        .hero-grid {
            display: flex;
            align-items: center;
            gap: 50px;
            flex-wrap: wrap;
        }
        .hero-left {
            flex: 1 1 50%;
            min-width: 300px;
        }
        .hero-right {
            flex: 1 1 40%;
            min-width: 280px;
        }
        .hero-right img {
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-card-hover);
            width: 100%;
            object-fit: cover;
            aspect-ratio: 16/12;
        }
        .hero-badge {
            display: inline-block;
            background: rgba(212, 160, 23, 0.12);
            color: var(--color-accent);
            font-weight: 600;
            font-size: 0.875rem;
            padding: 6px 14px;
            border-radius: 20px;
            margin-bottom: 16px;
            letter-spacing: 0.5px;
            border: 1px solid rgba(212, 160, 23, 0.25);
        }
        .hero-title {
            font-size: clamp(2rem, 4vw, 3rem);
            font-weight: 700;
            color: var(--color-primary);
            line-height: 1.25;
            margin-bottom: 16px;
            letter-spacing: 0.3px;
        }
        .hero-subtitle {
            font-size: 1.125rem;
            color: var(--color-text-secondary);
            line-height: 1.7;
            margin-bottom: 28px;
            max-width: 480px;
        }
        .hero-btns {
            display: flex;
            gap: 14px;
            flex-wrap: wrap;
        }
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            padding: 13px 28px;
            font-weight: 600;
            font-size: 1rem;
            border-radius: var(--radius-btn);
            transition: all 0.3s ease;
            letter-spacing: 0.3px;
            white-space: nowrap;
        }
        .btn-primary {
            background: var(--color-cta-green);
            color: #fff;
            box-shadow: 0 4px 14px rgba(15, 123, 78, 0.3);
        }
        .btn-primary:hover {
            background: var(--color-cta-green-hover);
            box-shadow: 0 6px 20px rgba(15, 123, 78, 0.4);
            transform: translateY(-2px);
            color: #fff;
        }
        .btn-outline {
            background: #fff;
            color: var(--color-primary-light);
            border: 2px solid var(--color-primary-light);
        }
        .btn-outline:hover {
            background: #f0f7fb;
            border-color: var(--color-primary);
            color: var(--color-primary);
            transform: translateY(-2px);
        }
        .btn-gold {
            background: var(--color-accent);
            color: #fff;
            box-shadow: 0 4px 16px rgba(212, 160, 23, 0.35);
        }
        .btn-gold:hover {
            background: var(--color-accent-hover);
            box-shadow: 0 6px 22px rgba(212, 160, 23, 0.5);
            transform: translateY(-2px);
            color: #fff;
        }

        @media (max-width: 768px) {
            .hero-grid {
                flex-direction: column-reverse;
                gap: 30px;
                text-align: center;
            }
            .hero-left {
                flex: 1 1 auto;
                min-width: auto;
            }
            .hero-right {
                flex: 1 1 auto;
                min-width: auto;
                max-width: 400px;
                margin: 0 auto;
            }
            .hero-subtitle {
                max-width: 100%;
            }
            .hero-btns {
                justify-content: center;
            }
            .hero-section {
                min-height: auto;
                padding-top: calc(var(--header-height) + 20px);
                padding-bottom: 40px;
            }
        }

        /* ========== SECTION TITLES ========== */
        .section-label {
            display: inline-block;
            font-size: 0.875rem;
            font-weight: 600;
            color: var(--color-accent);
            letter-spacing: 1px;
            text-transform: uppercase;
            margin-bottom: 8px;
        }
        .section-title {
            font-size: clamp(1.5rem, 3vw, 2rem);
            font-weight: 700;
            color: var(--color-primary);
            margin-bottom: 12px;
            line-height: 1.3;
        }
        .section-desc {
            font-size: 1.05rem;
            color: var(--color-text-secondary);
            max-width: 600px;
            line-height: 1.7;
        }
        .section-header {
            text-align: center;
            margin-bottom: 48px;
        }
        .section-header .section-desc {
            margin: 0 auto;
        }

        /* ========== FEATURES GRID (3x2) ========== */
        .features-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: var(--grid-gap);
        }
        .feature-card {
            background: var(--color-white);
            border-radius: var(--radius-card);
            padding: var(--card-padding);
            box-shadow: var(--shadow-card);
            transition: all 0.35s ease;
            text-align: center;
            border: 1px solid transparent;
            position: relative;
            overflow: hidden;
        }
        .feature-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 40px;
            height: 3px;
            background: var(--color-accent);
            border-radius: 0 0 4px 4px;
            opacity: 0;
            transition: opacity 0.35s ease;
        }
        .feature-card:hover {
            transform: translateY(-6px);
            box-shadow: var(--shadow-card-hover);
            border-color: #e0e8f0;
        }
        .feature-card:hover::before {
            opacity: 1;
        }
        .feature-icon {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 56px;
            height: 56px;
            border-radius: 50%;
            background: rgba(212, 160, 23, 0.1);
            color: var(--color-accent);
            font-size: 1.5rem;
            margin-bottom: 16px;
            transition: all 0.35s ease;
        }
        .feature-card:hover .feature-icon {
            background: rgba(212, 160, 23, 0.18);
            box-shadow: var(--shadow-gold-glow);
        }
        .feature-card h4 {
            font-size: 1.15rem;
            font-weight: 700;
            color: var(--color-primary);
            margin-bottom: 8px;
        }
        .feature-card p {
            font-size: 0.95rem;
            color: var(--color-text-secondary);
            line-height: 1.6;
        }

        @media (max-width: 768px) {
            .features-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 16px;
            }
            .feature-card {
                padding: 22px 16px;
            }
        }
        @media (max-width: 520px) {
            .features-grid {
                grid-template-columns: 1fr;
            }
        }

        /* ========== SERVICES MASONRY ========== */
        .services-masonry {
            display: grid;
            grid-template-columns: repeat(6, 1fr);
            gap: 20px;
            align-items: start;
        }
        .service-card {
            background: var(--color-white);
            border-radius: var(--radius-card);
            overflow: hidden;
            box-shadow: var(--shadow-card);
            transition: all 0.35s ease;
            border: 1px solid transparent;
        }
        .service-card:hover {
            transform: scale(1.02);
            box-shadow: var(--shadow-card-hover);
            border-color: #e0e8f0;
        }
        .service-card.wide {
            grid-column: span 4;
        }
        .service-card.narrow {
            grid-column: span 2;
        }
        .service-card img {
            width: 100%;
            aspect-ratio: 16/9;
            object-fit: cover;
        }
        .service-card-body {
            padding: 20px 24px 24px;
        }
        .service-card-body h4 {
            font-size: 1.1rem;
            font-weight: 700;
            color: var(--color-primary);
            margin-bottom: 6px;
        }
        .service-card-body p {
            font-size: 0.9rem;
            color: var(--color-text-secondary);
            line-height: 1.6;
            margin-bottom: 12px;
        }
        .service-card-body .text-link {
            font-weight: 600;
            color: var(--color-primary-light);
            font-size: 0.9rem;
            display: inline-flex;
            align-items: center;
            gap: 4px;
            transition: color 0.25s ease;
        }
        .service-card-body .text-link:hover {
            color: var(--color-primary);
        }
        .service-card-body .text-link i {
            transition: transform 0.25s ease;
        }
        .service-card-body .text-link:hover i {
            transform: translateX(3px);
        }

        @media (max-width: 768px) {
            .services-masonry {
                grid-template-columns: 1fr;
                gap: 16px;
            }
            .service-card.wide,
            .service-card.narrow {
                grid-column: span 1;
            }
        }

        /* ========== PROCESS STEPS ========== */
        .process-steps {
            display: flex;
            gap: 30px;
            justify-content: center;
            flex-wrap: wrap;
        }
        .process-step {
            flex: 1 1 200px;
            max-width: 260px;
            text-align: center;
            position: relative;
        }
        .process-step:not(:last-child)::after {
            content: '';
            position: absolute;
            top: 32px;
            right: -15px;
            width: 30px;
            height: 2px;
            background: #d0dce6;
        }
        .step-circle {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 64px;
            height: 64px;
            border-radius: 50%;
            background: var(--color-primary);
            color: #fff;
            font-size: 1.4rem;
            font-weight: 700;
            margin-bottom: 14px;
            font-family: var(--font-en);
            box-shadow: 0 4px 14px rgba(10, 76, 123, 0.3);
            transition: all 0.3s ease;
        }
        .process-step:hover .step-circle {
            background: var(--color-accent);
            box-shadow: var(--shadow-gold-glow);
            transform: scale(1.06);
        }
        .process-step h5 {
            font-size: 1.05rem;
            font-weight: 700;
            color: var(--color-primary);
            margin-bottom: 4px;
        }
        .process-step p {
            font-size: 0.9rem;
            color: var(--color-text-secondary);
            line-height: 1.5;
        }

        @media (max-width: 768px) {
            .process-steps {
                flex-direction: column;
                align-items: center;
                gap: 20px;
            }
            .process-step:not(:last-child)::after {
                display: none;
            }
            .process-step {
                max-width: 100%;
            }
        }

        /* ========== COMPARISON / SCENARIO ========== */
        .comparison-row {
            display: flex;
            align-items: stretch;
            gap: 0;
            margin-bottom: 40px;
            border-radius: var(--radius-card);
            overflow: hidden;
            box-shadow: var(--shadow-card);
            flex-wrap: wrap;
        }
        .comparison-row.reverse {
            flex-direction: row-reverse;
        }
        .comparison-text {
            flex: 1 1 50%;
            min-width: 300px;
            padding: 40px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            background: var(--color-white);
        }
        .comparison-text.dark-panel {
            background: var(--color-deep-panel);
            color: #fff;
        }
        .comparison-text.dark-panel h3 {
            color: #fff;
        }
        .comparison-text.dark-panel p {
            color: #d0dce6;
        }
        .comparison-text.dark-panel ul li {
            color: #c8d6e0;
        }
        .comparison-text h3 {
            font-size: 1.4rem;
            font-weight: 700;
            color: var(--color-primary);
            margin-bottom: 10px;
            line-height: 1.3;
        }
        .comparison-text p {
            font-size: 0.95rem;
            color: var(--color-text-secondary);
            line-height: 1.7;
            margin-bottom: 12px;
        }
        .comparison-text ul {
            display: flex;
            flex-direction: column;
            gap: 8px;
        }
        .comparison-text ul li {
            font-size: 0.9rem;
            color: var(--color-text-secondary);
            padding-left: 18px;
            position: relative;
            line-height: 1.6;
        }
        .comparison-text ul li::before {
            content: '';
            position: absolute;
            left: 0;
            top: 8px;
            width: 7px;
            height: 7px;
            border-radius: 50%;
            background: var(--color-accent);
        }
        .comparison-text.dark-panel ul li::before {
            background: var(--color-accent);
        }
        .comparison-image {
            flex: 1 1 45%;
            min-width: 280px;
        }
        .comparison-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            min-height: 320px;
        }

        @media (max-width: 768px) {
            .comparison-row,
            .comparison-row.reverse {
                flex-direction: column;
            }
            .comparison-text {
                padding: 28px 20px;
                min-width: auto;
            }
            .comparison-image img {
                min-height: 220px;
                aspect-ratio: 16/9;
            }
        }

        /* ========== FAQ ACCORDION ========== */
        .faq-list {
            max-width: 800px;
            margin: 0 auto;
        }
        .faq-item {
            border-bottom: 1px solid #dce4ed;
        }
        .faq-item summary {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 18px 8px;
            font-weight: 700;
            font-size: 1.05rem;
            color: var(--color-primary);
            cursor: pointer;
            list-style: none;
            transition: all 0.3s ease;
            gap: 12px;
        }
        .faq-item summary::-webkit-details-marker {
            display: none;
        }
        .faq-item summary .arrow-icon {
            flex-shrink: 0;
            width: 28px;
            height: 28px;
            border-radius: 50%;
            background: #eef2f6;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 0.8rem;
            color: var(--color-primary-light);
            transition: all 0.35s ease;
        }
        .faq-item[open] summary {
            color: var(--color-primary);
        }
        .faq-item[open] summary .arrow-icon {
            background: rgba(212, 160, 23, 0.15);
            color: var(--color-accent);
            transform: rotate(180deg);
        }
        .faq-item .faq-answer {
            padding: 0 8px 18px;
            font-size: 0.95rem;
            color: var(--color-text-secondary);
            line-height: 1.7;
        }
        .faq-item[open] {
            background: #f8fbfe;
        }

        /* ========== CTA SECTION ========== */
        .cta-section {
            position: relative;
            background-color: var(--color-primary);
            background-image: url('/assets/images/backpic/back-2.webp');
            background-size: cover;
            background-position: center;
            background-blend-mode: overlay;
            text-align: center;
            padding: 70px 20px;
            border-radius: 0;
        }
        .cta-section::before {
            content: '';
            position: absolute;
            inset: 0;
            background: rgba(10, 76, 123, 0.7);
            z-index: 1;
        }
        .cta-inner {
            position: relative;
            z-index: 2;
            max-width: 650px;
            margin: 0 auto;
        }
        .cta-inner h2 {
            font-size: clamp(1.6rem, 3vw, 2.2rem);
            font-weight: 700;
            color: #fff;
            margin-bottom: 12px;
            line-height: 1.3;
        }
        .cta-inner p {
            color: #d0dce6;
            font-size: 1rem;
            margin-bottom: 24px;
            line-height: 1.6;
        }
        .cta-inner .btn-gold {
            font-size: 1.1rem;
            padding: 15px 36px;
            letter-spacing: 0.5px;
        }
        .cta-trust {
            margin-top: 16px;
            font-size: 0.85rem;
            color: #b0c5d4;
            letter-spacing: 0.3px;
        }

        /* ========== FOOTER ========== */
        .site-footer {
            background: #e8ecf1;
            padding: 48px 0 24px;
            color: var(--color-text-secondary);
            font-size: 0.9rem;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 32px;
        }
        .footer-brand .logo-link {
            margin-bottom: 10px;
        }
        .footer-brand p {
            line-height: 1.6;
            max-width: 300px;
        }
        .footer-links h5 {
            font-weight: 700;
            color: var(--color-primary);
            margin-bottom: 12px;
            font-size: 0.95rem;
        }
        .footer-links ul {
            display: flex;
            flex-direction: column;
            gap: 6px;
        }
        .footer-links ul li a {
            color: var(--color-text-secondary);
            font-size: 0.875rem;
            transition: color 0.25s ease;
        }
        .footer-links ul li a:hover {
            color: var(--color-primary-light);
        }
        .footer-bottom {
            border-top: 1px solid #d4dce4;
            padding-top: 16px;
            text-align: center;
            font-size: 0.85rem;
            color: #7a8a99;
        }

        @media (max-width: 768px) {
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 24px;
                text-align: center;
            }
            .footer-brand p {
                max-width: 100%;
            }
            .footer-brand .logo-link {
                justify-content: center;
            }
        }

        /* ========== UTILITY ========== */
        .highlight-gold {
            color: var(--color-accent);
            font-weight: 700;
        }
        .text-center {
            text-align: center;
        }
        @media (max-width: 768px) {
            .hide-mobile {
                display: none;
            }
        }