:root {
            --primary-color: #1a5fb4;
            --secondary-color: #0d8a72;
            --accent-color: #e95420;
            --light-color: #f8f9fa;
            --dark-color: #2c3e50;
            --gray-color: #6c757d;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: #333;
            line-height: 1.6;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
        }
        .hero-section {
            background: linear-gradient(135deg, var(--primary-color) 0%, #0d4a9e 100%);
            color: white;
            padding: 6rem 0;
            position: relative;
            overflow: hidden;
        }
        .hero-section::before {
            content: '';
            position: absolute;
            top: -50%;
            right: -20%;
            width: 70%;
            height: 200%;
            background: rgba(255,255,255,0.05);
            transform: rotate(30deg);
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 2.5rem;
            font-weight: 700;
            color: var(--dark-color);
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 4px;
            background: var(--accent-color);
            border-radius: 2px;
        }
        .text-center .section-title::after {
            left: 50%;
            transform: translateX(-50%);
        }
        .service-card {
            border-radius: 10px;
            overflow: hidden;
            transition: all 0.3s ease;
            border: 1px solid #e9ecef;
            height: 100%;
        }
        .service-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
            border-color: var(--primary-color);
        }
        .service-icon {
            width: 70px;
            height: 70px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: white;
            font-size: 1.8rem;
        }
        .feature-box {
            padding: 2rem;
            background: white;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: transform 0.3s;
            height: 100%;
        }
        .feature-box:hover {
            transform: translateY(-5px);
        }
        .portfolio-item {
            position: relative;
            overflow: hidden;
            border-radius: 10px;
            margin-bottom: 30px;
        }
        .portfolio-img {
            transition: transform 0.5s;
            height: 250px;
            object-fit: cover;
            width: 100%;
        }
        .portfolio-item:hover .portfolio-img {
            transform: scale(1.05);
        }
        .portfolio-overlay {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            background: rgba(0,0,0,0.7);
            color: white;
            padding: 1.5rem;
            transform: translateY(100%);
            transition: transform 0.3s;
        }
        .portfolio-item:hover .portfolio-overlay {
            transform: translateY(0);
        }
        .testimonial-card {
            background: white;
            border-radius: 10px;
            padding: 2rem;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            margin-bottom: 30px;
            height: 100%;
            border-left: 4px solid var(--primary-color);
        }
        .client-logo {
            height: 60px;
            object-fit: contain;
            filter: grayscale(100%);
            opacity: 0.7;
            transition: all 0.3s;
        }
        .client-logo:hover {
            filter: grayscale(0);
            opacity: 1;
        }
        .contact-info-box {
            background: white;
            padding: 2rem;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            text-align: center;
            margin-bottom: 30px;
            transition: all 0.3s;
            height: 100%;
        }
        .contact-info-box:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }
        .contact-icon {
            width: 60px;
            height: 60px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: white;
            font-size: 1.5rem;
        }
        .btn-primary-custom {
            background: linear-gradient(135deg, var(--primary-color), #0d4a9e);
            border: none;
            padding: 0.75rem 2rem;
            border-radius: 50px;
            font-weight: 600;
            transition: all 0.3s;
        }
        .btn-primary-custom:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(26, 95, 180, 0.3);
        }
        .footer {
            background: var(--dark-color);
            color: #ddd;
            padding-top: 3rem;
        }
        .footer a {
            color: #ddd;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: white;
        }
        .footer-bottom {
            background: rgba(0,0,0,0.2);
            padding: 1.5rem 0;
            margin-top: 3rem;
        }
        .flink {
            display: inline-block;
            padding: 0.5rem 1.2rem;
            margin: 0.3rem;
            background: rgba(255,255,255,0.1);
            border-radius: 5px;
            transition: all 0.3s;
            color: #ddd;
            border: 1px solid rgba(255,255,255,0.1);
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-3px);
            text-decoration: none;
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            color: white;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 4rem 0;
            }
            .section-title {
                font-size: 1.8rem;
            }
            .navbar-nav {
                text-align: center;
                padding-top: 1rem;
            }
        }