:root {
            --primary-color: #0d6efd;
            --secondary-color: #6f42c1;
            --accent-color: #20c997;
            --dark-color: #212529;
            --light-color: #f8f9fa;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            line-height: 1.8;
            color: #333;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5 {
            font-weight: 700;
            color: var(--dark-color);
        }
        .navbar {
            background: rgba(13, 110, 253, 0.95);
            backdrop-filter: blur(10px);
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
        }
        .nav-link {
            font-weight: 500;
            transition: color 0.3s;
            margin: 0 5px;
        }
        .nav-link:hover {
            color: #ffc107 !important;
            transform: translateY(-2px);
        }
        .hero-section {
            background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
            color: white;
            padding: 120px 0;
            position: relative;
            overflow: hidden;
        }
        .hero-section h1 {
            font-size: 3.5rem;
            margin-bottom: 1.5rem;
            color: white;
            text-shadow: 2px 2px 8px rgba(0,0,0,0.2);
        }
        .hero-section p {
            font-size: 1.3rem;
            opacity: 0.9;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 12px 30px;
            border-radius: 50px;
            font-weight: 600;
            transition: all 0.3s ease;
        }
        .btn-primary:hover {
            background-color: #0b5ed7;
            border-color: #0a58ca;
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(13, 110, 253, 0.3);
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 50px;
            text-align: center;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--accent-color);
            border-radius: 2px;
        }
        .card {
            border: none;
            border-radius: 15px;
            overflow: hidden;
            transition: transform 0.4s ease, box-shadow 0.4s ease;
            height: 100%;
            box-shadow: 0 8px 20px rgba(0,0,0,0.08);
        }
        .card:hover {
            transform: translateY(-15px);
            box-shadow: 0 20px 40px rgba(0,0,0,0.15);
        }
        .card-img-top {
            height: 220px;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        .card:hover .card-img-top {
            transform: scale(1.05);
        }
        .icon-box {
            width: 80px;
            height: 80px;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 25px;
            color: white;
            font-size: 2rem;
        }
        .flink {
            display: inline-block;
            background: var(--light-color);
            padding: 12px 25px;
            margin: 10px;
            border-radius: 10px;
            text-decoration: none;
            color: var(--dark-color);
            font-weight: 500;
            transition: all 0.3s ease;
            border: 2px solid transparent;
        }
        .flink:hover {
            background: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
            transform: scale(1.05);
        }
        .friendlink {
            background-color: #f8f9fa;
            padding: 80px 0;
        }
        footer {
            background-color: var(--dark-color);
            color: #adb5bd;
            padding-top: 60px;
        }
        footer a {
            color: #adb5bd;
            text-decoration: none;
            transition: color 0.3s;
        }
        footer a:hover {
            color: white;
        }
        .social-icons a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 45px;
            height: 45px;
            background: rgba(255,255,255,0.1);
            border-radius: 50%;
            margin-right: 12px;
            transition: all 0.3s;
        }
        .social-icons a:hover {
            background: var(--primary-color);
            transform: rotate(15deg);
        }
        @media (max-width: 768px) {
            .hero-section h1 {
                font-size: 2.5rem;
            }
            .hero-section p {
                font-size: 1.1rem;
            }
            .section-title {
                font-size: 2rem;
            }
        }
        .content-text {
            text-align: justify;
            font-size: 1.05rem;
            margin-bottom: 25px;
        }
        .highlight {
            background-color: rgba(32, 201, 151, 0.1);
            border-left: 5px solid var(--accent-color);
            padding: 20px;
            margin: 30px 0;
            border-radius: 0 10px 10px 0;
        }