/* roulang page: index */
/* CSS Reset & Variables */
        *,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
        
        :root{
            --color-primary:#1A5C3A;
            --color-primary-dark:#144A2E;
            --color-accent:#F4A261;
            --color-accent-dark:#E08D3A;
            --color-bg:#FAFAF8;
            --color-text:#2D2D2D;
            --color-text-secondary:#5A5A5A;
            --color-text-light:#FFFFFF;
            --color-card-bg:#FFFFFF;
            --color-footer-bg:#2D2D2D;
            --color-footer-text:#CCCCCC;
            --color-traditional-bg:#F3F3F0;
            --color-solution-bg:rgba(26,92,58,0.05);
            --color-border-subtle:#E8E8E4;
            
            --font-display:'PingFang SC','Microsoft YaHei','Helvetica Neue',sans-serif;
            --font-body:'PingFang SC','Microsoft YaHei','Segoe UI',sans-serif;
            
            --shadow-card:0 2px 12px rgba(0,0,0,0.04);
            --shadow-card-hover:0 8px 24px rgba(0,0,0,0.08);
            --shadow-nav:0 1px 8px rgba(0,0,0,0.06);
            
            --radius-card:12px;
            --radius-btn:8px;
            --radius-input:6px;
            --radius-faq:8px;
            
            --spacing-section:80px;
            --spacing-section-mobile:48px;
            --spacing-card:32px;
            --spacing-card-mobile:20px;
            --spacing-grid:24px;
        }
        
        html{scroll-behavior:smooth;scroll-padding-top:64px}
        
        body{
            font-family:var(--font-body);
            font-size:16px;
            line-height:1.7;
            color:var(--color-text);
            background-color:var(--color-bg);
            -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 0.2s ease}
        ul{list-style:none}
        button{cursor:pointer;border:none;background:none;font-family:inherit}
        
        /* Container */
        .container{
            max-width:1200px;
            margin:0 auto;
            padding:0 24px;
        }
        
        /* Navigation */
        .site-header{
            position:sticky;
            top:0;
            z-index:100;
            background:#FFFFFF;
            height:64px;
            transition:box-shadow 0.3s ease;
        }
        .site-header.scrolled{box-shadow:var(--shadow-nav)}
        
        .main-nav{height:100%}
        .nav-container{
            max-width:1200px;
            margin:0 auto;
            padding:0 24px;
            height:100%;
            display:flex;
            align-items:center;
            justify-content:space-between;
        }
        
        .logo-link{
            display:flex;
            align-items:center;
            font-family:var(--font-display);
            font-weight:700;
            font-size:22px;
        }
        .logo-text{color:var(--color-text)}
        .logo-highlight{color:var(--color-primary)}
        
        .nav-links{
            display:flex;
            align-items:center;
            gap:28px;
        }
        .nav-link{
            font-size:15px;
            font-weight:500;
            color:var(--color-text-secondary);
            padding:8px 0;
            position:relative;
            transition:color 0.2s ease;
        }
        .nav-link:hover{color:var(--color-primary)}
        .nav-link.active{color:var(--color-primary)}
        .nav-link.active::after{
            content:'';
            position:absolute;
            bottom:0;
            left:0;
            width:100%;
            height:2px;
            background:var(--color-primary);
            border-radius:1px;
        }
        .nav-cta-button{
            background:var(--color-primary);
            color:#FFFFFF !important;
            padding:10px 20px !important;
            border-radius:var(--radius-btn);
            transition:background 0.2s ease,transform 0.2s ease;
        }
        .nav-cta-button:hover{
            background:var(--color-primary-dark);
            transform:translateY(-1px);
        }
        .nav-cta-button.active::after{display:none}
        
        .menu-toggle{
            display:none;
            flex-direction:column;
            gap:5px;
            width:28px;
            height:22px;
            justify-content:space-between;
        }
        .menu-toggle span{
            display:block;
            width:100%;
            height:2px;
            background:var(--color-text);
            border-radius:1px;
            transition:transform 0.3s ease,opacity 0.3s ease;
        }
        .menu-toggle.active span:nth-child(1){transform:translateY(8px) rotate(45deg)}
        .menu-toggle.active span:nth-child(2){opacity:0}
        .menu-toggle.active span:nth-child(3){transform:translateY(-8px) rotate(-45deg)}
        
        /* Hero Section */
        .hero-section{
            padding:var(--spacing-section) 24px;
            background:var(--color-bg);
            min-height:85vh;
            display:flex;
            align-items:center;
        }
        .hero-container{
            max-width:1200px;
            margin:0 auto;
            display:grid;
            grid-template-columns:1fr 1fr;
            gap:60px;
            align-items:center;
            width:100%;
        }
        .hero-content{text-align:left}
        .hero-title{
            font-family:var(--font-display);
            font-size:40px;
            font-weight:700;
            line-height:1.2;
            color:var(--color-text);
            margin-bottom:20px;
        }
        .hero-subtitle{
            font-size:18px;
            line-height:1.6;
            color:var(--color-text-secondary);
            margin-bottom:36px;
        }
        .hero-cta-group{
            display:flex;
            gap:16px;
            margin-bottom:28px;
        }
        .btn{
            display:inline-block;
            font-family:var(--font-body);
            font-size:16px;
            font-weight:600;
            padding:14px 32px;
            border-radius:var(--radius-btn);
            text-align:center;
            transition:all 0.2s ease;
            cursor:pointer;
        }
        .btn-primary{
            background:var(--color-primary);
            color:#FFFFFF;
        }
        .btn-primary:hover{
            background:var(--color-primary-dark);
            transform:translateY(-2px);
        }
        .btn-secondary{
            background:transparent;
            color:var(--color-primary);
            border:2px solid var(--color-primary);
        }
        .btn-secondary:hover{
            background:rgba(26,92,58,0.1);
            transform:translateY(-2px);
        }
        .trust-badges{
            display:flex;
            gap:24px;
            flex-wrap:wrap;
        }
        .trust-item{
            font-size:13px;
            color:var(--color-text-secondary);
            display:flex;
            align-items:center;
            gap:6px;
        }
        .trust-icon{
            color:var(--color-primary);
            font-weight:700;
            font-size:16px;
        }
        
        .hero-image{
            position:relative;
            border-radius:var(--radius-card);
            overflow:hidden;
            box-shadow:var(--shadow-card);
        }
        .hero-img{
            width:100%;
            height:auto;
            object-fit:cover;
            aspect-ratio:4/3;
        }
        .hero-image-overlay{
            position:absolute;
            top:0;
            left:0;
            width:100%;
            height:100%;
            background:linear-gradient(135deg, rgba(26,92,58,0.15) 0%, transparent 70%);
            pointer-events:none;
        }
        
        /* Section Generic */
        .section-header{
            text-align:center;
            margin-bottom:48px;
        }
        .section-title{
            font-family:var(--font-display);
            font-size:32px;
            font-weight:700;
            line-height:1.3;
            color:var(--color-text);
            margin-bottom:12px;
        }
        .section-description{
            font-size:16px;
            color:var(--color-text-secondary);
            max-width:600px;
            margin:0 auto;
        }
        
        /* Features Section */
        .features-section{
            padding:var(--spacing-section) 0;
            background:#FFFFFF;
        }
        .features-grid{
            display:grid;
            grid-template-columns:repeat(3,1fr);
            gap:var(--spacing-grid);
        }
        .feature-card{
            background:var(--color-card-bg);
            border-radius:var(--radius-card);
            padding:var(--spacing-card);
            box-shadow:var(--shadow-card);
            transition:transform 0.2s ease,box-shadow 0.2s ease;
            text-align:left;
        }
        .feature-card:hover{
            transform:translateY(-4px);
            box-shadow:var(--shadow-card-hover);
        }
        .feature-icon{
            width:48px;
            height:48px;
            border-radius:50%;
            background:rgba(244,162,97,0.1);
            display:flex;
            align-items:center;
            justify-content:center;
            margin-bottom:20px;
            overflow:hidden;
        }
        .feature-icon-img{
            width:32px;
            height:32px;
            object-fit:cover;
            border-radius:50%;
        }
        .feature-title{
            font-family:var(--font-display);
            font-size:22px;
            font-weight:600;
            color:var(--color-text);
            margin-bottom:8px;
        }
        .feature-description{
            font-size:15px;
            color:var(--color-text-secondary);
            line-height:1.6;
        }
        
        /* Cases Section */
        .cases-section{
            padding:var(--spacing-section) 0;
            background:var(--color-bg);
        }
        .cases-grid{
            display:grid;
            grid-template-columns:repeat(3,1fr);
            gap:var(--spacing-grid);
        }
        .case-card{
            background:var(--color-card-bg);
            border-radius:var(--radius-card);
            overflow:hidden;
            box-shadow:var(--shadow-card);
            transition:transform 0.2s ease,box-shadow 0.2s ease;
            display:flex;
            flex-direction:column;
        }
        .case-card:hover{
            transform:translateY(-4px);
            box-shadow:var(--shadow-card-hover);
        }
        .case-image{
            width:100%;
            aspect-ratio:16/10;
            overflow:hidden;
        }
        .case-image img{
            width:100%;
            height:100%;
            object-fit:cover;
            transition:transform 0.3s ease;
        }
        .case-card:hover .case-image img{transform:scale(1.03)}
        .case-content{
            padding:20px;
            flex:1;
            display:flex;
            flex-direction:column;
        }
        .case-title{
            font-family:var(--font-display);
            font-size:18px;
            font-weight:600;
            line-height:1.5;
            color:var(--color-text);
            margin-bottom:8px;
        }
        .case-summary{
            font-size:14px;
            line-height:1.6;
            color:var(--color-text-secondary);
            margin-bottom:16px;
            flex:1;
        }
        .case-tags{
            display:flex;
            gap:8px;
            flex-wrap:wrap;
        }
        .tag{
            display:inline-block;
            background:var(--color-accent);
            color:#FFFFFF;
            font-size:12px;
            font-weight:500;
            padding:2px 10px;
            border-radius:20px;
            line-height:1.6;
        }
        
        /* Solutions Comparison */
        .solutions-section{
            padding:var(--spacing-section) 0;
            background:#FFFFFF;
        }
        .comparison-wrapper{
            display:flex;
            align-items:stretch;
            justify-content:center;
            gap:20px;
        }
        .comparison-column{
            flex:1;
            max-width:440px;
            padding:40px 32px;
            border-radius:var(--radius-card);
            display:flex;
            flex-direction:column;
        }
        .comparison-traditional{background:var(--color-traditional-bg)}
        .comparison-solution{background:var(--color-solution-bg)}
        .comparison-vs{
            display:flex;
            align-items:center;
            justify-content:center;
            flex-shrink:0;
        }
        .comparison-vs span{
            display:flex;
            align-items:center;
            justify-content:center;
            width:48px;
            height:48px;
            border-radius:50%;
            background:#FFFFFF;
            color:var(--color-primary);
            font-weight:700;
            font-size:16px;
            box-shadow:var(--shadow-card);
        }
        .comparison-column-title{
            font-family:var(--font-display);
            font-size:22px;
            font-weight:600;
            color:var(--color-text);
            margin-bottom:28px;
            text-align:center;
        }
        .comparison-list{
            margin-bottom:28px;
            flex:1;
        }
        .comparison-item{
            display:flex;
            align-items:flex-start;
            gap:12px;
            margin-bottom:16px;
            font-size:15px;
            line-height:1.6;
            color:var(--color-text-secondary);
        }
        .comparison-icon{
            font-size:18px;
            font-weight:700;
            flex-shrink:0;
            margin-top:2px;
        }
        .comparison-item.negative .comparison-icon{color:#C0392B}
        .comparison-item.positive .comparison-icon{color:var(--color-primary)}
        .comparison-cta{
            text-align:center;
        }
        .comparison-note{
            font-size:14px;
            color:#999;
            font-style:italic;
        }
        
        /* FAQ */
        .faq-section{
            padding:var(--spacing-section) 0;
            background:var(--color-bg);
        }
        .faq-wrapper{
            max-width:800px;
            margin:0 auto;
        }
        .faq-item{
            background:var(--color-card-bg);
            border-radius:var(--radius-faq);
            margin-bottom:12px;
            box-shadow:var(--shadow-card);
            overflow:hidden;
        }
        .faq-item.active{border-left:4px solid var(--color-primary)}
        .faq-question{
            width:100%;
            display:flex;
            align-items:center;
            justify-content:space-between;
            padding:20px 24px;
            cursor:pointer;
            text-align:left;
            background:none;
            transition:background 0.2s ease;
        }
        .faq-question:hover{background:rgba(26,92,58,0.02)}
        .faq-question-text{
            font-family:var(--font-display);
            font-size:18px;
            font-weight:600;
            color:var(--color-text);
            flex:1;
            padding-right:20px;
        }
        .faq-toggle{
            width:22px;
            height:22px;
            position:relative;
            flex-shrink:0;
        }
        .faq-toggle::before,
        .faq-toggle::after{
            content:'';
            position:absolute;
            background:var(--color-primary);
            border-radius:1px;
            transition:transform 0.3s ease;
        }
        .faq-toggle::before{
            width:2px;
            height:14px;
            top:4px;
            left:10px;
        }
        .faq-toggle::after{
            width:14px;
            height:2px;
            top:10px;
            left:4px;
        }
        .faq-item.active .faq-toggle::before{transform:rotate(90deg)}
        
        .faq-answer{
            max-height:0;
            overflow:hidden;
            transition:max-height 0.35s ease,padding 0.35s ease;
        }
        .faq-item.active .faq-answer{
            max-height:300px;
            padding:0 24px 20px;
        }
        .faq-answer-content{
            font-size:15px;
            line-height:1.7;
            color:var(--color-text-secondary);
        }
        
        /* CTA Section */
        .cta-section{
            background:linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
            padding:var(--spacing-section) 24px;
            text-align:center;
        }
        .cta-container{max-width:800px;margin:0 auto}
        .cta-content{color:#FFFFFF}
        .cta-title{
            font-family:var(--font-display);
            font-size:32px;
            font-weight:700;
            line-height:1.3;
            margin-bottom:16px;
            color:#FFFFFF;
        }
        .cta-subtitle{
            font-size:18px;
            line-height:1.6;
            margin-bottom:36px;
            opacity:0.95;
        }
        .btn-cta{
            background:var(--color-accent);
            color:#FFFFFF;
            font-size:18px;
            padding:16px 40px;
            font-weight:700;
        }
        .btn-cta:hover{
            background:var(--color-accent-dark);
            transform:translateY(-2px);
        }
        
        /* Contact Form */
        .contact-section{
            padding:var(--spacing-section) 0;
            background:#FFFFFF;
        }
        .contact-form{max-width:700px;margin:0 auto}
        .form-grid{
            display:grid;
            grid-template-columns:1fr 1fr;
            gap:20px;
        }
        .form-group-full{grid-column:1/-1}
        .form-group{display:flex;flex-direction:column}
        .form-label{
            font-size:14px;
            font-weight:600;
            color:var(--color-text);
            margin-bottom:6px;
        }
        .form-input{
            padding:12px 16px;
            font-size:15px;
            font-family:var(--font-body);
            border:1px solid var(--color-border-subtle);
            border-radius:var(--radius-input);
            background:#FAFAFA;
            color:var(--color-text);
            transition:border-color 0.2s ease,box-shadow 0.2s ease;
        }
        .form-input:focus{
            outline:none;
            border-color:var(--color-primary);
            box-shadow:0 0 0 3px rgba(26,92,58,0.1);
        }
        .form-textarea{resize:vertical;min-height:100px}
        .form-submit{
            margin-top:28px;
            text-align:center;
        }
        .btn-submit{min-width:200px}
        
        /* Footer */
        .site-footer{
            background:var(--color-footer-bg);
            color:var(--color-footer-text);
            padding:60px 24px 30px;
        }
        .footer-container{max-width:1200px;margin:0 auto}
        .footer-grid{
            display:grid;
            grid-template-columns:1.5fr 1fr 1fr 1fr;
            gap:40px;
            margin-bottom:40px;
        }
        .footer-logo{
            font-family:var(--font-display);
            font-size:22px;
            font-weight:700;
            color:#FFFFFF;
            margin-bottom:16px;
        }
        .footer-logo-highlight{color:var(--color-accent)}
        .footer-brand-description{
            font-size:14px;
            line-height:1.7;
        }
        .footer-title{
            font-family:var(--font-display);
            font-size:16px;
            font-weight:600;
            color:#FFFFFF;
            margin-bottom:16px;
        }
        .footer-links li,.footer-contact-item{margin-bottom:10px}
        .footer-links a,.footer-contact-item span{font-size:14px;transition:color 0.2s ease}
        .footer-links a:hover{color:#FFFFFF}
        .footer-contact-item{
            display:flex;
            align-items:center;
            gap:8px;
            font-size:14px;
        }
        .footer-icon{flex-shrink:0}
        .footer-social{
            display:flex;
            gap:16px;
            flex-wrap:wrap;
        }
        .social-icon{
            width:40px;
            height:40px;
            border-radius:50%;
            background:rgba(255,255,255,0.1);
            display:flex;
            align-items:center;
            justify-content:center;
            cursor:pointer;
            transition:background 0.2s ease;
            font-size:14px;
            color:#FFFFFF;
        }
        .social-icon:hover{background:rgba(255,255,255,0.2)}
        .footer-bottom{
            border-top:1px solid rgba(255,255,255,0.1);
            padding-top:24px;
            text-align:center;
        }
        .footer-copyright{font-size:13px;color:var(--color-footer-text)}
        
        /* Responsive */
        @media(max-width:1024px){
            .hero-title{font-size:34px}
            .section-title{font-size:28px}
            .features-grid{grid-template-columns:repeat(2,1fr)}
            .cases-grid{grid-template-columns:repeat(2,1fr)}
            .footer-grid{grid-template-columns:1fr 1fr;gap:30px}
        }
        
        @media(max-width:768px){
            .menu-toggle{display:flex}
            .nav-links{
                position:fixed;
                top:64px;
                left:0;
                width:100%;
                background:#FFFFFF;
                flex-direction:column;
                padding:32px;
                gap:16px;
                box-shadow:var(--shadow-nav);
                transform:translateX(-100%);
                transition:transform 0.3s ease;
                z-index:99;
            }
            .nav-links.active{transform:translateX(0)}
            .nav-link{font-size:18px}
            
            .hero-container{grid-template-columns:1fr;text-align:center}
            .hero-image{order:1}
            .hero-content{order:2;text-align:center}
            .hero-cta-group{justify-content:center}
            .trust-badges{justify-content:center}
            
            .features-grid{grid-template-columns:1fr}
            .cases-grid{grid-template-columns:1fr}
            
            .comparison-wrapper{flex-direction:column;align-items:center;gap:16px}
            .comparison-vs{margin:8px 0}
            
            .footer-grid{grid-template-columns:1fr}
            .form-grid{grid-template-columns:1fr}
            
            .hero-title{font-size:30px}
            .section-title{font-size:24px}
            .hero-section{min-height:auto;padding-top:40px;padding-bottom:48px}
        }
        
        @media(max-width:480px){
            .hero-title{font-size:26px}
            .section-title{font-size:22px}
            .btn{padding:12px 24px;font-size:15px}
            .hero-cta-group{flex-direction:column;align-items:center}
        }