/* 响应式设计 */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 40px;
    }
    
    .about-content,
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: block;
    }
    
    .nav ul {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background-color: rgba(26, 58, 143, 0.98);
        flex-direction: column;
        align-items: center;
        padding: 20px 0;
        backdrop-filter: blur(10px);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s;
    }
    
    .nav ul.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav li {
        margin: 15px 0;
    }
    
    .hero {
        padding: 150px 0 100px;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-description {
        font-size: 18px;
    }
    
    .section-title h2 {
        font-size: 28px;
    }
    
    section {
        padding: 60px 0;
    }
    
    .product-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .hero-title {
        font-size: 28px;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
}