:root {
            --primary-color: #1a237e;
            --secondary-color: #ff6f00;
            --accent-color: #4fc3f7;
            --dark-color: #0d1b2a;
            --light-color: #f8f9fa;
            --gray-color: #6c757d;
        }
        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
            color: #333;
            line-height: 1.8;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--dark-color);
        }
        .navbar {
            background-color: rgba(13, 27, 42, 0.95);
            padding: 1rem 0;
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        .navbar-brand {
            font-size: 1.8rem;
            font-weight: 800;
            color: white !important;
        }
        .navbar-brand span {
            color: var(--accent-color);
        }
        .nav-link {
            color: rgba(255,255,255,0.9) !important;
            font-weight: 600;
            margin: 0 0.5rem;
            transition: color 0.3s;
        }
        .nav-link:hover {
            color: var(--accent-color) !important;
        }
        .hero-section {
            background: linear-gradient(rgba(13, 27, 42, 0.85), rgba(26, 35, 126, 0.9)), url('https://images.unsplash.com/photo-1516450360452-9312f5e86fc7?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80') no-repeat center center/cover;
            color: white;
            padding: 10rem 0;
            text-align: center;
        }
        .hero-title {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            text-shadow: 2px 2px 8px rgba(0,0,0,0.5);
        }
        .hero-subtitle {
            font-size: 1.3rem;
            max-width: 800px;
            margin: 0 auto 2rem;
            opacity: 0.9;
        }
        .btn-primary-custom {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            padding: 0.8rem 2.5rem;
            font-weight: 600;
            border-radius: 50px;
            transition: all 0.3s;
        }
        .btn-primary-custom:hover {
            background-color: #e65100;
            border-color: #e65100;
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(255, 111, 0, 0.3);
        }
        .section-title {
            position: relative;
            padding-bottom: 1rem;
            margin-bottom: 3rem;
            text-align: center;
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--secondary-color);
            border-radius: 2px;
        }
        .card-hover {
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border: none;
            border-radius: 12px;
            overflow: hidden;
            height: 100%;
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .icon-box {
            width: 80px;
            height: 80px;
            background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            color: white;
            font-size: 2rem;
        }
        .service-card {
            border-top: 5px solid var(--accent-color);
        }
        .project-img {
            height: 250px;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .project-card:hover .project-img {
            transform: scale(1.05);
        }
        .news-card {
            border-left: 4px solid var(--primary-color);
        }
        .contact-info-box {
            background-color: var(--light-color);
            border-radius: 12px;
            padding: 2rem;
            height: 100%;
            border-left: 5px solid var(--secondary-color);
        }
        .contact-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .form-control-custom {
            border-radius: 8px;
            border: 1px solid #ddd;
            padding: 0.8rem 1rem;
            transition: all 0.3s;
        }
        .form-control-custom:focus {
            border-color: var(--accent-color);
            box-shadow: 0 0 0 0.25rem rgba(79, 195, 247, 0.25);
        }
        .friendlink {
            background-color: #f8f9fa;
            padding: 4rem 0;
        }
        .flink {
            display: inline-block;
            background: white;
            padding: 0.8rem 1.5rem;
            margin: 0.5rem;
            border-radius: 50px;
            color: var(--dark-color);
            text-decoration: none;
            font-weight: 600;
            transition: all 0.3s;
            border: 2px solid transparent;
        }
        .flink:hover {
            border-color: var(--secondary-color);
            color: var(--secondary-color);
            transform: translateY(-3px);
        }
        footer {
            background-color: var(--dark-color);
            color: rgba(255,255,255,0.8);
            padding: 4rem 0 2rem;
        }
        .footer-links a {
            color: rgba(255,255,255,0.7);
            text-decoration: none;
            transition: color 0.3s;
            display: block;
            margin-bottom: 0.5rem;
        }
        .footer-links a:hover {
            color: var(--accent-color);
        }
        .copyright {
            border-top: 1px solid rgba(255,255,255,0.1);
            padding-top: 2rem;
            margin-top: 3rem;
            text-align: center;
            font-size: 0.9rem;
            color: rgba(255,255,255,0.6);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--secondary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s;
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--primary-color);
            color: white;
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.5rem;
            }
            .hero-subtitle {
                font-size: 1.1rem;
            }
            .navbar-nav {
                text-align: center;
                background-color: rgba(13, 27, 42, 0.98);
                padding: 1rem;
                border-radius: 10px;
                margin-top: 1rem;
            }
        }