/* 移动端响应式适配（≤768px）- 简洁头部 + 汉堡展开菜单，避免重叠 */
@media (max-width: 768px) {
    .container {
        width: 100%;
        padding: 0 16px;
        box-sizing: border-box;
    }
    /* 头部只保留 Logo + 汉堡，单行不换行 */
    .header .container {
        padding: 12px 16px;
        flex-direction: row;
        flex-wrap: nowrap;
        justify-content: space-between;
        align-items: center;
    }
    /* 导航面板相对 header 定位，铺满整屏宽，避免被 container 限制偏左 */
    .header .nav {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        width: 100%;
        z-index: 1001;
        pointer-events: none;
    }
    .header .nav ul {
        pointer-events: auto;
        display: flex;
        flex-direction: column;
        align-items: center;
        position: fixed;
        top: 56px;
        left: 0;
        right: 0;
        width: 100%;
        max-height: 0;
        overflow: hidden;
        margin: 0;
        padding: 0 !important;
        background: rgba(0, 0, 0, 0.55);
        backdrop-filter: blur(8px);
        box-shadow: 0 8px 24px rgba(0,0,0,0.2);
        transition: max-height 0.3s ease, background 0.3s ease;
        list-style: none;
        box-sizing: border-box;
    }
    .header .nav ul.active {
        max-height: 85vh;
        overflow-y: auto;
        padding: 16px 0 24px 0 !important;
    }
    /* 滚动过 banner 后导航面板与头部一致为黑色 */
    .header-transparent.header-scrolled .nav ul.active {
        background: rgba(0, 0, 0, 0.98);
        backdrop-filter: none;
    }
    .header .nav ul > li {
        margin: 0;
        width: 100%;
        max-width: 100%;
        text-align: center;
        border-bottom: 1px solid rgba(255,255,255,0.08);
        display: flex;
        flex-direction: column;
        align-items: center;
    }
    .header .nav ul > li:last-child {
        border-bottom: none;
    }
    .header .nav ul > li > a {
        display: block;
        width: 100%;
        padding: 14px 24px;
        font-size: 15px;
        color: #fff !important;
        text-shadow: none;
        text-decoration: none;
        text-align: center;
        box-sizing: border-box;
    }
    /* 核心模块子菜单：点击「核心模块」后再展开 4 个子项，整体居中 */
    .header .nav .nav-dropdown {
        position: static;
        width: 100%;
        max-width: 280px;
        margin: 0 auto;
        background: rgba(255,255,255,0.06);
        padding: 0 !important;
        box-shadow: none;
        border-radius: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.25s ease;
        display: flex;
        flex-direction: column;
        align-items: center;
        list-style: none;
        text-align: center;
    }
    .header .nav .nav-has-dropdown.expanded .nav-dropdown {
        max-height: 280px;
        padding-bottom: 8px;
    }
    .header .nav .nav-has-dropdown > a {
        border-bottom: none;
    }
    .header .nav .nav-has-dropdown > a::after {
        content: '';
        display: inline-block;
        margin-left: 6px;
        vertical-align: middle;
        border: 5px solid transparent;
        border-top-color: currentColor;
    }
    .header .nav .nav-has-dropdown.expanded > a::after {
        border-top-color: transparent;
        border-bottom-color: currentColor;
        margin-bottom: 2px;
    }
    .header .nav .nav-dropdown li {
        margin: 0;
        padding: 0;
        border: none;
        width: 100%;
        text-align: center;
    }
    .header .nav .nav-dropdown li a {
        display: block;
        width: 100%;
        padding: 10px 24px;
        font-size: 14px;
        color: rgba(255,255,255,0.9) !important;
        text-align: center;
        box-sizing: border-box;
    }
    .header .nav ul li a:hover,
    .header .nav .nav-dropdown li a:hover {
        color: #5dade2 !important;
        background: rgba(255,255,255,0.06);
    }
    .header .logo {
        flex-shrink: 0;
    }
    .header .logo a img {
        height: 44px !important;
        max-width: 70vw !important;
        transform: none !important;
    }
    /* 汉堡按钮显示在移动端 */
    .mobile-menu-btn {
        display: flex !important;
        margin-left: auto;
        align-items: center;
        justify-content: center;
    }
    .header-transparent .mobile-menu-btn span {
        background-color: #fff;
    }
    .section-main-title {
        font-size: 24px;
        margin-bottom: 24px;
        padding: 0 10px;
    }
    .core-business .section-main-title,
    .news .section-main-title {
        padding: 0 10px;
        margin-bottom: 24px;
    }
    .hero,
    .homepage .hero {
        min-height: 320px;
        height: 50vh;
    }
    .banner,
    .banner.banner-no-overlay,
    .smart-energy-hero {
        min-height: 320px !important;
        height: 50vh !important;
    }
    .core-business .container,
    .news .container {
        padding: 0 16px 40px;
    }
    .core-business,
    .news {
        padding: 40px 0;
    }
    .business-grid {
        gap: 20px;
    }
    .business-item {
        margin-left: 0;
        margin-right: 0;
        border-left: 1px solid #eee;
        border-right: 1px solid #eee;
    }
    .business-image {
        height: 220px;
    }
    .news-content .business-image {
        height: 200px;
    }
    .news-content .business-content {
        padding: 12px 16px 32px;
    }
    .news-content .business-content h3 {
        font-size: 15px;
        -webkit-line-clamp: 2;
    }
    .news-more-wrap {
        margin-top: 28px;
    }
    .news-more-btn {
        font-size: 15px;
    }
    .slider-btn {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }
    .slider-indicators {
        bottom: 12px;
    }
    .hero-content h2 {
        font-size: 1.35rem;
        padding: 0 15px;
    }
    .footer {
        padding: 40px 0 24px;
    }
    .footer .container {
        padding: 0 16px;
    }
    .footer-content {
        grid-template-columns: 1fr;
        gap: 28px;
        text-align: center;
        margin-bottom: 24px;
    }
    .footer-section h2 {
        font-size: 16px;
        margin-bottom: 12px;
    }
    .company-info {
        grid-column: 1 / -1;
    }
    .company-contact-row {
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 8px;
        text-align: center;
        flex-wrap: wrap;
    }
    .footer-bottom {
        margin-top: 16px;
    }
    .footer-bottom p {
        font-size: 12px;
    }
    section {
        padding: 40px 0;
    }
    .about,
    .philosophy,
    .vision,
    .technology,
    .news-list,
    .services {
        padding: 40px 0;
    }
    .feedback-form {
        flex-direction: column;
        gap: 20px;
    }
    .content .container {
        padding: 24px 20px !important;
    }

    /* 关于我们页 */
    .vision-mission {
        padding: 32px 0 24px;
    }
    .vision-mission-items {
        grid-template-columns: 1fr;
        gap: 24px;
        padding: 0 8px;
    }
    .vision-mission-item h3 {
        font-size: 16px;
    }
    .vision-mission-item p {
        font-size: 14px;
    }
    .about-intro {
        flex-direction: column;
        gap: 24px;
        padding: 24px 0;
    }
    .about-intro-text h2 {
        font-size: 22px;
    }
    .about-intro-text p {
        font-size: 15px;
    }

    /* 新闻列表页 */
    .news-list .container {
        padding: 0 16px 40px;
    }
    .news-list .news-items {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    .news-card-title {
        font-size: 14px;
    }

    /* 服务案例、解决方案等网格 */
    .services-grid,
    .solution-list {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    .banner-content h2 {
        font-size: 1.4rem;
        padding: 0 16px;
    }
}