:root {
            --primary-color: #0056b3;
            --secondary-color: #17a2b8;
            --accent-color: #28a745;
            --light-color: #f8f9fa;
            --dark-color: #343a40;
            --transition: all 0.3s ease;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: #333;
            line-height: 1.6;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
            color: var(--primary-color) !important;
        }
        .navbar-nav .nav-link {
            font-weight: 500;
            padding: 0.5rem 1rem;
            transition: var(--transition);
        }
        .navbar-nav .nav-link:hover, .navbar-nav .nav-link.active {
            color: var(--primary-color) !important;
            transform: translateY(-2px);
        }
        .hero-section {
            background: linear-gradient(rgba(0, 84, 179, 0.85), rgba(0, 84, 179, 0.9)), url('https://images.unsplash.com/photo-1497366216548-37526070297c?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 10rem 0;
            margin-top: 76px;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 3rem;
            color: var(--dark-color);
            font-weight: 700;
        }
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 4px;
            background: var(--primary-color);
        }
        .text-center .section-title:after {
            left: 50%;
            transform: translateX(-50%);
        }
        .card-hover {
            transition: var(--transition);
            border: none;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            height: 100%;
        }
        .card-hover:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .icon-box {
            width: 70px;
            height: 70px;
            background: var(--primary-color);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            font-size: 1.8rem;
        }
        .stats-box {
            text-align: center;
            padding: 2rem;
            background: var(--light-color);
            border-radius: 10px;
            transition: var(--transition);
        }
        .stats-box:hover {
            background: var(--primary-color);
            color: white;
        }
        .stats-box:hover .display-4 {
            color: white;
        }
        .stats-box .display-4 {
            color: var(--primary-color);
            font-weight: 700;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            transition: var(--transition);
        }
        .btn-primary:hover {
            background-color: #004494;
            border-color: #004494;
            transform: translateY(-3px);
        }
        .partner-logo {
            filter: grayscale(100%);
            opacity: 0.7;
            transition: var(--transition);
            max-height: 60px;
            padding: 1rem;
        }
        .partner-logo:hover {
            filter: grayscale(0);
            opacity: 1;
        }
        .friendlink-container {
            background: var(--light-color);
            padding: 3rem 0;
            border-radius: 10px;
        }
        .flink {
            display: inline-block;
            margin: 0.5rem 1rem;
            padding: 0.5rem 1rem;
            background: white;
            border-radius: 50px;
            color: var(--dark-color);
            text-decoration: none;
            transition: var(--transition);
            border: 1px solid #dee2e6;
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: translateY(-3px);
            text-decoration: none;
        }
        footer {
            background: var(--dark-color);
            color: #adb5bd;
        }
        footer a {
            color: #adb5bd;
            text-decoration: none;
            transition: var(--transition);
        }
        footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .social-icons a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background: rgba(255,255,255,0.1);
            border-radius: 50%;
            margin-right: 0.75rem;
            transition: var(--transition);
        }
        .social-icons a:hover {
            background: var(--primary-color);
            transform: translateY(-3px);
        }
        .news-card {
            border-left: 4px solid var(--primary-color);
        }
        .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;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            z-index: 1000;
        }
        .back-to-top.active {
            opacity: 1;
            visibility: visible;
        }
        .back-to-top:hover {
            background: #004494;
            color: white;
            transform: translateY(-5px);
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 6rem 0;
            }
            .display-4 {
                font-size: 2.5rem;
            }
        }
