:root {
            --primary-color: #0d6efd;
            --secondary-color: #6c757d;
            --accent-color: #20c997;
            --dark-color: #212529;
            --light-color: #f8f9fa;
            --transition-speed: 0.3s;
        }
        body {
            font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
            color: #333;
            line-height: 1.6;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
        }
        .nav-link {
            font-weight: 500;
            transition: color var(--transition-speed);
        }
        .nav-link:hover {
            color: var(--accent-color) !important;
        }
        .hero-section {
            background: linear-gradient(135deg, rgba(13, 110, 253, 0.9) 0%, rgba(32, 201, 151, 0.85) 100%), url('https://images.unsplash.com/photo-1558494949-ef010cbdcc31?ixlib=rb-4.0.3&auto=format&fit=crop&w=1950&q=80') no-repeat center center;
            background-size: cover;
            color: white;
            padding: 120px 0;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 50px;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 4px;
            background-color: var(--accent-color);
        }
        .text-center .section-title::after {
            left: 50%;
            transform: translateX(-50%);
        }
        .card {
            border: none;
            border-radius: 12px;
            box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
            transition: transform var(--transition-speed), box-shadow var(--transition-speed);
            height: 100%;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
        }
        .card-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .service-card, .case-card {
            height: 100%;
        }
        .case-img {
            height: 220px;
            object-fit: cover;
            border-top-left-radius: 12px;
            border-top-right-radius: 12px;
        }
        .team-member img {
            width: 150px;
            height: 150px;
            object-fit: cover;
        }
        .contact-info i {
            width: 24px;
        }
        footer {
            background-color: var(--dark-color);
            color: var(--light-color);
        }
        .footer-link {
            color: #adb5bd;
            text-decoration: none;
            transition: color var(--transition-speed);
        }
        .footer-link:hover {
            color: white;
        }
        .flink {
            display: inline-block;
            background-color: #f1f1f1;
            color: #333;
            padding: 8px 20px;
            margin: 5px 10px;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 500;
            transition: all var(--transition-speed);
            border: 1px solid #dee2e6;
        }
        .flink:hover {
            background-color: var(--primary-color);
            color: white;
            transform: translateY(-3px);
        }
        .friendlink {
            background-color: #f8f9fa;
            padding: 60px 0;
        }
        .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;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.3s, visibility 0.3s;
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background-color: var(--dark-color);
            color: white;
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2rem;
            }
            .hero-section {
                padding: 80px 0;
            }
        }
        .hover-shadow {
            transition: box-shadow var(--transition-speed);
        }
        .hover-shadow:hover {
            box-shadow: 0 .5rem 1rem rgba(0,0,0,.15)!important;
        }