:root {
            --primary-color: #1a5276;
            --secondary-color: #d35400;
            --accent-color: #27ae60;
            --light-bg: #f8f9fa;
            --dark-text: #2c3e50;
            --shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: var(--dark-text);
            line-height: 1.6;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .navbar {
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: var(--shadow);
            padding: 1rem 0;
            transition: var(--transition);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color);
        }
        .navbar-brand span {
            color: var(--secondary-color);
        }
        .nav-link {
            font-weight: 600;
            margin: 0 0.5rem;
            color: var(--dark-text);
            transition: var(--transition);
        }
        .nav-link:hover, .nav-link.active {
            color: var(--secondary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(26, 82, 118, 0.85), rgba(26, 82, 118, 0.9)), url('https://images.unsplash.com/photo-1544551763-46a013bb70d5?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80') no-repeat center center/cover;
            color: white;
            padding: 8rem 0 6rem;
            margin-top: 76px;
        }
        .hero-title {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            text-shadow: 2px 2px 8px rgba(0,0,0,0.3);
        }
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2.5rem;
            }
        }
        .section-padding {
            padding: 5rem 0;
        }
        .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 {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        .card-img-top {
            height: 220px;
            object-fit: cover;
            transition: var(--transition);
        }
        .card:hover .card-img-top {
            transform: scale(1.05);
        }
        .icon-box {
            width: 70px;
            height: 70px;
            background-color: rgba(26, 82, 118, 0.1);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1.5rem;
            color: var(--primary-color);
            font-size: 1.8rem;
        }
        .service-card {
            border-top: 5px solid var(--primary-color);
            padding: 2rem 1.5rem;
            text-align: center;
            background-color: white;
        }
        .service-card:hover {
            border-top-color: var(--secondary-color);
        }
        .stats-box {
            background-color: var(--primary-color);
            color: white;
            padding: 2.5rem;
            border-radius: 12px;
            text-align: center;
            transition: var(--transition);
        }
        .stats-box:hover {
            background-color: #14415e;
        }
        .stats-number {
            font-size: 3rem;
            font-weight: 800;
            margin-bottom: 0.5rem;
            color: white;
        }
        .project-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 2rem;
        }
        .project-item {
            position: relative;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: var(--shadow);
        }
        .project-overlay {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            background: linear-gradient(transparent, rgba(0,0,0,0.8));
            color: white;
            padding: 2rem 1.5rem 1.5rem;
            transform: translateY(100%);
            transition: var(--transition);
        }
        .project-item:hover .project-overlay {
            transform: translateY(0);
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            border-radius: 50px;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: #14415e;
            border-color: #14415e;
            transform: translateY(-3px);
            box-shadow: 0 7px 14px rgba(26, 82, 118, 0.25);
        }
        .btn-secondary {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            border-radius: 50px;
            transition: var(--transition);
        }
        .btn-secondary:hover {
            background-color: #b84703;
            border-color: #b84703;
            transform: translateY(-3px);
            box-shadow: 0 7px 14px rgba(211, 84, 0, 0.25);
        }
        .contact-info-box {
            background-color: var(--light-bg);
            padding: 2rem;
            border-radius: 12px;
            border-left: 5px solid var(--secondary-color);
            margin-bottom: 1.5rem;
            transition: var(--transition);
        }
        .contact-info-box:hover {
            transform: translateX(10px);
        }
        .footer {
            background-color: #1a252f;
            color: #bdc3c7;
            padding: 4rem 0 2rem;
        }
        .footer h5 {
            color: #ecf0f1;
            margin-bottom: 1.5rem;
        }
        .footer a {
            color: #bdc3c7;
            text-decoration: none;
            transition: var(--transition);
        }
        .footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .copyright {
            border-top: 1px solid #2c3e50;
            padding-top: 2rem;
            margin-top: 3rem;
            text-align: center;
        }
        .flink {
            display: inline-block;
            background-color: rgba(255,255,255,0.1);
            padding: 0.5rem 1.2rem;
            margin: 0.5rem;
            border-radius: 50px;
            transition: var(--transition);
            color: #ecf0f1;
            text-decoration: none;
        }
        .flink:hover {
            background-color: var(--secondary-color);
            color: white;
            transform: translateY(-3px);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 50px;
            height: 50px;
            background-color: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            cursor: pointer;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            z-index: 1000;
            box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--secondary-color);
            transform: translateY(-5px);
        }
        .timeline {
            position: relative;
            padding-left: 2rem;
            border-left: 3px solid var(--primary-color);
            margin-left: 1rem;
        }
        .timeline-item {
            position: relative;
            margin-bottom: 2.5rem;
        }
        .timeline-item:before {
            content: '';
            position: absolute;
            left: -2.5rem;
            top: 0;
            width: 16px;
            height: 16px;
            border-radius: 50%;
            background-color: var(--primary-color);
            border: 3px solid white;
            box-shadow: 0 0 0 3px var(--primary-color);
        }
        .form-control, .form-select {
            padding: 0.75rem 1rem;
            border-radius: 8px;
            border: 1px solid #dee2e6;
            transition: var(--transition);
        }
        .form-control:focus, .form-select:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 0.25rem rgba(26, 82, 118, 0.25);
        }
        .accordion-button {
            font-weight: 600;
            padding: 1.2rem 1.5rem;
        }
        .accordion-button:not(.collapsed) {
            background-color: rgba(26, 82, 118, 0.05);
            color: var(--primary-color);
        }
        .accordion-button:focus {
            box-shadow: 0 0 0 0.25rem rgba(26, 82, 118, 0.25);
        }
        .badge-custom {
            background-color: var(--accent-color);
            color: white;
            padding: 0.4rem 0.8rem;
            border-radius: 50px;
            font-size: 0.85rem;
            font-weight: 600;
        }
        .mobile-menu-btn {
            display: none;
        }
        @media (max-width: 992px) {
            .mobile-menu-btn {
                display: block;
            }
            .navbar-collapse {
                background-color: white;
                padding: 1rem;
                border-radius: 12px;
                box-shadow: var(--shadow);
                margin-top: 1rem;
            }
            .hero-title {
                font-size: 2.8rem;
            }
        }
        @media (max-width: 768px) {
            .section-padding {
                padding: 3rem 0;
            }
            .hero-section {
                padding: 6rem 0 4rem;
            }
            .stats-number {
                font-size: 2.5rem;
            }
        }