/* 响应式设计 - 移动设备适配 */

@media (max-width: 1200px) {
    /* 中等屏幕调整 */
    .container {
        width: 95%;
    }
}

@media (max-width: 992px) {
    /* 平板设备调整 */
    .section-title {
        font-size: 2rem;
    }
    
    .overview-content {
        flex-direction: column;
    }
    
    .overview-image {
        margin-top: 30px;
    }
}

@media (max-width: 768px) {
    /* 小平板和大型手机 */
    .header .container {
        flex-direction: column;
        padding: 10px 0;
    }
    
    .logo {
        margin-bottom: 10px;
    }
    
    .nav {
        margin-bottom: 10px;
    }
    
    .contact-phone {
        margin-top: 10px;
    }
    
    .page-header {
        padding: 80px 0;
    }
    
    .page-header h2 {
        font-size: 2.2rem;
    }
    
    .timeline::before {
        left: 50px;
    }
    
    .timeline-item, .timeline-item:nth-child(odd) {
        flex-direction: row;
        text-align: left;
    }
    
    .timeline-content {
        width: calc(100% - 150px);
        margin-left: 50px;
    }
    
    .product-showcase {
        grid-template-columns: 1fr;
    }
    
    .product-detail {
        flex-direction: column;
    }
    
    .product-gallery {
        margin-bottom: 30px;
    }
}

@media (max-width: 576px) {
    /* 小型手机 */
    .section-title {
        font-size: 1.8rem;
    }
    
    .section-title::after {
        width: 60px;
    }
    
    .page-header h2 {
        font-size: 1.8rem;
    }
    
    .page-header p {
        font-size: 1.1rem;
    }
    
    .timeline-year {
        width: 70px;
        height: 70px;
        font-size: 1.1rem;
    }
    
    .timeline-content {
        width: calc(100% - 120px);
        margin-left: 30px;
    }
    
    .tech-grid, .advantages-grid {
        grid-template-columns: 1fr;
    }
    
    .application-grid, .area-grid {
        grid-template-columns: 1fr;
    }
    
    .case-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .back-to-top {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
}

/* 移动端菜单样式 */
.menu-toggle {
    display: none;
    cursor: pointer;
    font-size: 1.5rem;
    color: #0066cc;
    padding: 5px;
}

@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }
    
    .nav {
        display: none;
        width: 100%;
    }
    
    .nav ul {
        flex-direction: column;
        align-items: center;
    }
    
    .nav li {
        margin: 5px 0;
    }
    
    .nav a {
        padding: 8px 0;
    }
}

/* 回到顶部按钮样式 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background-color: #0066cc;
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: #004a99;
    transform: translateY(-3px);
}