:root {
            --primary-color: #1a365d;
            --secondary-color: #c53030;
            --accent-color: #ed8936;
            --light-color: #f7fafc;
            --dark-color: #2d3748;
        }
        body {
            font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
            color: var(--dark-color);
            line-height: 1.8;
        }
        h1, h2, h3, h4 {
            font-weight: 700;
            color: var(--primary-color);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
        }
        .navbar-nav .nav-link {
            font-weight: 600;
            color: var(--dark-color) !important;
            transition: color 0.3s;
        }
        .navbar-nav .nav-link:hover {
            color: var(--secondary-color) !important;
        }
        .hero-section {
            background: linear-gradient(rgba(26, 54, 93, 0.85), rgba(26, 54, 93, 0.9)), url('https://images.unsplash.com/photo-1504307651254-35680f356dfd?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') no-repeat center center/cover;
            color: white;
            padding: 10rem 0;
            text-align: center;
        }
        .hero-section h1 {
            color: white;
            font-size: 3.5rem;
            margin-bottom: 1.5rem;
        }
        .section-padding {
            padding: 6rem 0;
        }
        .section-title {
            position: relative;
            margin-bottom: 3rem;
            text-align: center;
        }
        .section-title::after {
            content: '';
            position: absolute;
            width: 80px;
            height: 4px;
            background: var(--secondary-color);
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
        }
        .service-card, .project-card {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
            transition: transform 0.4s, box-shadow 0.4s;
            height: 100%;
        }
        .service-card:hover, .project-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
        }
        .service-icon {
            font-size: 3rem;
            color: var(--secondary-color);
            margin-bottom: 1.5rem;
        }
        .project-card img {
            height: 250px;
            object-fit: cover;
            transition: transform 0.5s;
        }
        .project-card:hover img {
            transform: scale(1.05);
        }
        .team-member {
            text-align: center;
            margin-bottom: 2rem;
        }
        .team-member img {
            width: 180px;
            height: 180px;
            border-radius: 50%;
            object-fit: cover;
            border: 5px solid var(--light-color);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            margin-bottom: 1.5rem;
        }
        .contact-info i {
            font-size: 1.5rem;
            color: var(--secondary-color);
            margin-right: 10px;
            width: 30px;
        }
        .contact-form .form-control {
            border-radius: 8px;
            border: 1px solid #ced4da;
            padding: 0.8rem 1rem;
            margin-bottom: 1.5rem;
            transition: border-color 0.3s, box-shadow 0.3s;
        }
        .contact-form .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 0.25rem rgba(26, 54, 93, 0.25);
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.8rem 2rem;
            font-weight: 600;
            border-radius: 8px;
            transition: background-color 0.3s, transform 0.3s;
        }
        .btn-primary:hover {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            transform: translateY(-3px);
        }
        .footer {
            background-color: var(--primary-color);
            color: white;
            padding: 4rem 0 2rem;
        }
        .footer a {
            color: #cbd5e0;
            text-decoration: none;
            transition: color 0.3s;
        }
        .footer a:hover {
            color: white;
        }
        .friendlink {
            background-color: var(--light-color);
            padding: 4rem 0;
        }
        .friendlink .flink {
            display: inline-block;
            margin: 0.5rem 1rem;
            padding: 0.5rem 1.5rem;
            background: white;
            border-radius: 50px;
            color: var(--primary-color);
            font-weight: 600;
            text-decoration: none;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: all 0.3s;
        }
        .friendlink .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: scale(1.05);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background: var(--secondary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            text-decoration: none;
            opacity: 0;
            transition: opacity 0.3s, transform 0.3s;
            z-index: 1000;
        }
        .back-to-top.visible {
            opacity: 1;
        }
        .back-to-top:hover {
            transform: scale(1.1);
            color: white;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .section-padding {
                padding: 4rem 0;
            }
            .navbar-nav {
                text-align: center;
                padding-top: 1rem;
            }
        }