.hero-gradient {
            background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 50%, #3b82f6 100%);
        }
        .course-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
        }
        .testimonial-card {
            transition: all 0.3s ease;
        }
        .testimonial-card:hover {
            transform: scale(1.03);
        }
        .login-modal, .payment-modal {
            transition: all 0.3s ease;
            opacity: 0;
            visibility: hidden;
        }
        .modal-active {
            opacity: 1;
            visibility: visible;
        }
        .nav-link::after {
            content: '';
            display: block;
            width: 0;
            height: 2px;
            background: #3b82f6;
            transition: width 0.3s;
        }
        .nav-link:hover::after {
            width: 100%;
        }