body {
      margin: 0;
      font-family: "Microsoft YaHei", sans-serif;
      line-height: 1.6;
      background: #fff;
    }

    header {
      background: var(--primary);
      color: white;
      padding: 1rem 2.5rem;
      display: flex;
      align-items: center;
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      width: 100%;
      z-index: 1000;
      box-sizing: border-box;
      justify-content: space-between;
    }

    /* 滚动后的样式 */
    header.scrolled {
      background: white;
      color: black;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
      width: 100%;
      margin-right: 0;
    }

    /* 让导航链接颜色也随之变化 */
    header.scrolled .main-nav a {
      color: black;
    }

    header.scrolled .main-nav a:hover {
      color: var(--primary);
    }

    /* LOGO 字体颜色变化 */
    header.scrolled .logo {
      color: black;
    }

    /* 菜单按钮颜色变化 */
    header.scrolled .nav-toggle {
      color: black;
    }

    .logo {
      font-size: 1.5em;
      font-weight: bold;
    }

    .main-nav {
      left: 0;
    }

    .main-nav ul {
      list-style: none;
      display: flex;
      gap: 3.5em;
      margin: 0 0 0 50px;
      padding: 0;
    }

    .main-nav ul > li {
      position: relative;
      z-index: 1;
    }

    .main-nav a {
      color: white;
      text-decoration: none;
      transition: color 0.3s;
      position: relative;
      z-index: 10;
    }

    .main-nav a:hover {
      color: var(--accent);
    }

    section {
      padding: 3em 2em;
      background: #f9f9f9;
      border-bottom: 1px solid #ddd;
    }

    h2 {
      color: var(--primary);
    }

    .category ul {
      list-style: none;
      padding-left: 0;
    }

    .category li,
    .grid .item {
      background: white;
      margin-bottom: 1em;
      padding: 1em;
      border-radius: 5px;
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
      transition: transform 0.3s;
    }

    .grid {
      display: flex;
      gap: 2em;
      flex-wrap: wrap;
    }

    .grid .item {
      flex: 1 1 200px;
    }

    .carousel {
      position: relative;
      overflow: hidden;
      max-width: 100%;
      height: 400px;
      margin-bottom: 2em;
    }

    .carousel img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      animation: fade 1s ease-in-out;
    }

    @keyframes fade {
      from {
        opacity: 0.4
      }

      to {
        opacity: 1
      }
    }

    .carousel-controls {
      position: absolute;
      width: 100%;
      top: 50%;
      display: flex;
      justify-content: space-between;
      transform: translateY(-50%);
    }

    .carousel-controls span {
      background: rgba(0, 0, 0, 0.5);
      color: #fff;
      padding: 0.5em;
      cursor: pointer;
    }

    .video-banner {
      position: relative;
      height: 500px;
      overflow: hidden;
    }

    .video-banner video {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .video-banner .overlay {
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background: rgba(0, 0, 0, 0.4);
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 2em;
      font-weight: bold;
    }

    .case-list,
    .news-list {
      display: flex;
      flex-wrap: wrap;
      gap: 1.5em;
    }

    .case-item,
    .news-item {
      flex: 1 1 300px;
      background: white;
      padding: 1em;
      border-radius: 6px;
      box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
      transition: transform 0.3s;
    }

    .case-item:hover,
    .news-item:hover {
      transform: translateY(-5px);
    }

    footer {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 1em 2em;
    }

    @media (max-width: 768px) {
      .main-nav ul {
        flex-direction: column;
        background: var(--primary);
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        display: none;
        margin-left: 50px;
      }

      .main-nav ul.show {
        display: flex;
      }

      .nav-toggle {
        display: block;
        cursor: pointer;
      }
    }

    #nav-menu li a {
      font-size: 20px;
      position: relative;
      z-index: 10;
    }

    .nav-toggle {
      display: none;
      font-size: 1.5em;
      color: white;
    }

    .grid .item:hover {
      transform: translateY(-5px);
    }

    .head {
      background: transparent;
    }

    body.subpage .head {
      background: #fff;
    }

    .banner {
      position: relative;
      width: 100%;
      height: 566px;
      overflow: hidden;
      margin-bottom: 2em;
      background: #000;
    }

    .banner-images {
      display: flex;
      transition: transform 0.6s cubic-bezier(.77, 0, .18, 1);
      height: 100%;
    }

    .banner-images img {
      width: 100%;
      height: 566px;
      object-fit: cover;
      flex-shrink: 0;
      flex-grow: 0;
      flex-basis: 100%;
      user-select: none;
      pointer-events: none;
    }

    .banner-controls {
      position: absolute;
      top: 50%;
      left: 0;
      right: 0;
      display: flex;
      justify-content: space-between;
      transform: translateY(-50%);
      z-index: 2;
    }

    .banner-controls span {
      background: rgba(0, 0, 0, 0.5);
      color: #fff;
      padding: 0.7em 1em;
      font-size: 2em;
      cursor: pointer;
      border-radius: 4px;
      margin: 0 10px;
      user-select: none;
    }

    .banner-indicators {
      position: absolute;
      bottom: 20px;
      left: 50%;
      transform: translateX(-50%);
      display: flex;
      gap: 12px;
      z-index: 2;
    }

    .banner-indicators span {
      display: block;
      width: 40px;
      height: 8px;
      background: rgba(255, 255, 255, 0.5);
      border-radius: 4px;
      cursor: pointer;
      transition: background 0.3s;
    }

    .banner-indicators span.active {
      background: var(--accent);
    }

    @media (max-width: 768px) {

      .banner,
      .banner-images img {
        height: 220px;
      }
    }

    .banner-item {
      position: relative;
      width: 100%;
      height: 566px;
      flex-shrink: 0;
      flex-grow: 0;
      flex-basis: 100%;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .banner-item img {
      width: 100%;
      height: 566px;
      object-fit: cover;
      user-select: none;
      pointer-events: none;
    }

    .banner-btn {
      position: absolute;
      bottom: 40px;
      left: 50%;
      transform: translateX(-50%);
      background: transparent;
      color: #fff;
      padding: 0.7em 2em;
      border-radius: 24px;
      font-size: 1.2em;
      font-weight: bold;
      text-decoration: none;
      border: 2px solid #fff;
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
      transition: background 0.3s, color 0.3s;
      z-index: 3;
    }

    .banner-btn:hover {
      background: #fff;
      color: var(--primary);
    }


    .nav-products {
      position: relative;
      z-index: 100;
    }

    .nav-products .nav-underline {
      display: none;
      position: absolute;
      left: 0;
      bottom: -6px;
      width: 100%;
      height: 3px;
      background: var(--accent);
      border-radius: 2px;
      transition: opacity 0.3s;
    }

    .nav-products:hover .nav-underline {
      display: block;
      opacity: 1;
    }

    .products-overlay {
      display: none;
      position: absolute;
      left: 0;
      top: 40px;
      width: 1200px;
      background: #fff;
      box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
      border-radius: 8px;
      padding: 2em;
      z-index: 999;
      min-height: 260px;
    }

    .nav-products:hover .products-overlay {
      display: flex;
    }

    .products-level1,
    .products-level2 {
      width: 140px;
      border-right: 1px solid #eee;
      padding-right: 1em;
    }

    .products-level1 ul,
    .products-level2 ul {
      list-style: none;
      padding: 0;
      margin: 0;
      display: flex;
      flex-direction: column;
      /* 纵向排列，每行一个分类 */
      gap: 0.5em;
      /* 分类之间间距 */
    }

    .products-level1 li,
    .products-level2 li {
      padding: 0.7em 1.5em;
      cursor: pointer;
      font-weight: bold;
      color: #000;
      border-radius: 4px;
      margin-bottom: 0;
      /* 去除下方间距 */
      transition: background 0.2s, color 0.2s;
      white-space: nowrap;
      /* 防止换行 */
    }

    .products-level1 li.active,
    .products-level1 li:hover,
    .products-level2 li.active,
    .products-level2 li:hover {
      background: #c3c2bf;
      color: var(--accent);
    }

    .products-list {
      flex: 1;
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 1.2em;
      padding-left: 2em;
    }

    .product-item {
      background: #f9f9f9;
      border-radius: 6px;
      padding: 1em;
      text-align: center;
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
      transition: box-shadow 0.2s;
    }

    .product-item img {
      width: 160px;
      height: 160px;
      object-fit: contain;
      margin-bottom: 0.7em;
      border-radius: 4px;
      background: #fff;
    }

    .product-item .name {
      font-size: 1em;
      color: #000;
      font-weight: bold;
    }

    .products-overlay .show {
      display: flex;
    }

    .products-center-section {
      padding: 4em 2em 2em 2em;
      background: #fff;
      text-align: center;
    }

    .products-center-title {
      font-size: 2.5em;
      font-weight: bold;
      color: var(--primary);
      margin-bottom: 0.5em;
    }

    .products-center-subtitle {
      font-size: 1.1em;
      color: #666;
      margin-bottom: 2em;
    }

    /* ── 首页产品中心：左树 + 右网格 ── */
    .index-product-container {
      display: flex;
      max-width: 1400px;
      margin: 0 auto;
      gap: 24px;
      padding: 0 1em;
    }

    .index-product-sidebar {
      width: 210px;
      flex-shrink: 0;
      background: #f7f8fa;
      border-radius: 10px;
      border: 1px solid rgba(0,0,0,0.06);
      overflow: hidden;
      align-self: flex-start;
    }

    /* 当侧边栏隐藏时，让主内容区域占满全宽并居中 */
    .index-product-sidebar[style*="display: none"] + .index-product-main {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
    }

    .index-sidebar-tree {
      list-style: none;
      margin: 0;
      padding: 6px 0;
    }

    .index-sidebar-tree .idx-l1 {
      border-bottom: 1px solid rgba(0,0,0,0.05);
    }
    .index-sidebar-tree .idx-l1:last-child {
      border-bottom: none;
    }

    .idx-l1-label {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 11px 16px;
      font-size: 0.93em;
      font-weight: 600;
      color: #333;
      cursor: pointer;
      transition: background 0.2s, color 0.2s;
      user-select: none;
    }
    .idx-l1-label:hover {
      background: rgba(var(--primary-rgb), 0.06);
    }
    .idx-l1-label.active {
      color: var(--accent);
    }
    .idx-l1-arrow {
      font-size: 0.55em;
      transition: transform 0.25s;
      color: #bbb;
      margin-left: 4px;
    }
    .idx-l1.open .idx-l1-arrow {
      transform: rotate(90deg);
    }

    .idx-l1-children {
      list-style: none;
      padding: 0 0 4px 0;
      margin: 0;
      display: none;
    }
    .idx-l1.open .idx-l1-children {
      display: block;
    }

    .idx-l2-item {
      padding: 8px 16px 8px 30px;
      font-size: 0.86em;
      color: #666;
      cursor: pointer;
      transition: background 0.15s, color 0.15s;
      border-left: 3px solid transparent;
    }
    .idx-l2-item:hover {
      background: rgba(var(--primary-rgb), 0.04);
      color: #333;
    }
    .idx-l2-item.active {
      color: var(--accent);
      border-left-color: var(--accent);
      background: rgba(var(--primary-rgb), 0.06);
      font-weight: 600;
    }

    .index-product-main {
      flex: 1;
      min-width: 0;
    }

    .index-product-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 16px;
    }

    .idx-product-card {
      background: #fff;
      border-radius: 10px;
      border: 1px solid rgba(0,0,0,0.07);
      overflow: hidden;
      cursor: pointer;
      transition: border-color 0.25s, box-shadow 0.25s, transform 0.25s;
      display: flex;
      flex-direction: column;
    }
    .idx-product-card:hover {
      border-color: rgba(var(--primary-rgb), 0.3);
      box-shadow: 0 4px 16px rgba(0,0,0,0.08);
      transform: translateY(-3px);
    }

    .idx-product-card-img {
      width: 100%;
      height: 150px;
      background: #fafafa;
      display: flex;
      align-items: center;
      justify-content: center;
      overflow: hidden;
      padding: 12px;
      box-sizing: border-box;
    }
    .idx-product-card-img img {
      max-width: 100%;
      max-height: 100%;
      object-fit: contain;
      transition: transform 0.3s;
    }
    .idx-product-card:hover .idx-product-card-img img {
      transform: scale(1.05);
    }

    .idx-product-card-body {
      padding: 12px 14px 14px;
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }
    .idx-product-card-name {
      font-size: 0.92em;
      font-weight: 700;
      color: #222;
      margin: 0;
      line-height: 1.4;
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }
    .idx-product-card-desc {
      font-size: 0.78em;
      color: #999;
      line-height: 1.5;
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
      margin: 0;
    }

    .index-product-more {
      text-align: center;
      margin-top: 24px;
      padding: 8px 0;
    }
    .index-product-more-btn {
      display: inline-block;
      padding: 10px 36px;
      border: 2px solid var(--accent);
      border-radius: 24px;
      color: var(--accent);
      font-size: 1em;
      font-weight: 600;
      text-decoration: none;
      transition: background 0.2s, color 0.2s;
    }
    .index-product-more-btn:hover {
      background: var(--accent);
      color: #fff;
    }

    @media (max-width: 1100px) {
      .index-product-grid { grid-template-columns: repeat(3, 1fr); }
    }
    @media (max-width: 800px) {
      .index-product-container { flex-direction: column; }
      .index-product-sidebar { width: 100%; }
      .index-product-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 500px) {
      .index-product-grid { grid-template-columns: 1fr; }
    }



    .solutions-section {
      background: #fff;
      text-align: center;
      padding: 4em 0 2em 0;
    }

    .solutions-list {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2em;
      width: 90%;
      margin: 0 auto;
    }

    .solution-card {
      background: #fff;
      border-radius: 16px;
      padding: 2em 1em 1.5em 1em;
      display: flex;
      flex-direction: column;
      align-items: center;
      transition: box-shadow 0.3s;
    }

    .solution-img-wrap {
      width: 100%;
      height: 220px;
      overflow: hidden;
      border-radius: 12px;
      margin-bottom: 1em;
      background: #fff;
      padding: 10px;
      box-sizing: border-box;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .solution-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: contain;
      transition: transform 0.3s;
      border-radius: 8px;
    }

    .solution-img-wrap:hover img {
      transform: scale(1.08);
    }

    .solution-name {
      font-size: 1.3em;
      font-weight: bold;
      color: var(--primary);
      margin-top: 0.5em;
      padding: 0.3em 0;
      border-radius: 6px;
      transition: color 0.3s, background 0.3s;
      cursor: pointer;
    }

    .solution-name:hover {
      color: var(--accent-hover);
      background: #f3f3f3;
    }

    .solution-desc {
      font-size: 1em;
      color: #666;
      margin-top: 0.3em;
      margin-bottom: 0.5em;
      min-height: 2em;
    }


    .news-section {
      background: #fff;
      text-align: center;
      padding: 4em 0 2em 0;
    }

    .news-title {
      font-size: 2.2em;
      color: var(--primary);
      font-weight: bold;
      margin-bottom: 0.3em;
    }

    .news-subtitle {
      font-size: 1.1em;
      color: #666;
      margin-bottom: 2em;
    }

    .news-carousel {
      position: relative;
      width: 90%;
      margin: 0 auto;
      min-height: 660px;
      overflow: hidden;
      /* 防止动画期间出现滚动条 */
    }

    .news-list {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2em;
      align-items: stretch;
      transition: transform 0.6s cubic-bezier(.77, 0, .18, 1);
      will-change: transform;
    }

    .news-item {
      background: #f9f9f9;
      border-radius: 16px;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    .news-img-wrap {
      width: 100%;
      height: 420px;
      overflow: hidden;
      border-radius: 16px 16px 0 0;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .news-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }

    .news-img-wrap:hover img {
      transform: scale(1.08);
    }

    .news-info {
      padding: 1em 1em 1.2em 1em;
      width: 100%;
      text-align: left;
    }

    .news-title-text {
      font-size: 1.2em;
      font-weight: bold;
      color: var(--primary);
      margin-bottom: 0.5em;
      transition: color 0.3s;
      cursor: pointer;
    }

    .news-title-text:hover {
      color: var(--accent-hover);
    }

    .news-date {
      font-size: 0.95em;
      color: #999;
    }

    .news-controls {
      position: absolute;
      top: 50%;
      left: -40px;
      right: -40px;
      display: flex;
      justify-content: space-between;
      transform: translateY(-50%);
      z-index: 2;
    }

    .news-controls span {
      background: rgba(0, 0, 0, 0.12);
      color: var(--primary);
      padding: 0.7em 1.2em;
      font-size: 2em;
      border-radius: 6px;
      cursor: pointer;
      user-select: none;
      transition: background 0.3s;
    }

    .news-controls span:hover {
      background: var(--accent);
      color: #fff;
    }


    .cases-section {
      background: #fff;
      text-align: center;
      padding: 3em 0 2em 0;
    }

    .cases-title {
      font-size: 2em;
      color: var(--primary);
      font-weight: bold;
      margin-bottom: 1em;
    }

    .cases-carousel {
      position: relative;
      width: 90%;
      margin: 0 auto;
      overflow: hidden;
      min-height: 420px;
    }

    .cases-list {
      display: flex;
      gap: 2em;
      transition: transform 0.6s cubic-bezier(.77, 0, .18, 1);
      will-change: transform;
    }

    .case-item {
      flex: 0 0 22%;
      /* 一屏4张，留点间距 */
      display: flex;
      flex-direction: column;
      align-items: center;
      background: none;
      box-shadow: none;
      border-radius: 0;
      padding: 0;
    }

    .case-img-wrap {
      width: 100%;
      height: 540px;
      overflow: hidden;
      border-radius: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      background: none;
      box-shadow: none;
    }

    .case-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
      border-radius: 0;
      background: none;
      box-shadow: none;
      display: block;
    }

    .case-img-wrap:hover img {
      transform: scale(1.08);
    }

    .cases-controls {
      position: absolute;
      top: 50%;
      left: -40px;
      right: -40px;
      display: flex;
      justify-content: space-between;
      transform: translateY(-50%);
      z-index: 2;
    }

    .cases-controls span {
      background: rgba(0, 0, 0, 0.12);
      color: var(--primary);
      padding: 0.7em 1.2em;
      font-size: 2em;
      border-radius: 6px;
      cursor: pointer;
      user-select: none;
      transition: background 0.3s;
    }

    .cases-controls span:hover {
      background: var(--accent);
      color: #fff;
    }

    /**解决方案**/

    .nav-solutions {
      position: relative;
      z-index: 100;
    }

    .nav-solutions .nav-underline {
      display: none;
      position: absolute;
      left: 0;
      bottom: -6px;
      width: 100%;
      height: 3px;
      background: var(--accent);
      border-radius: 2px;
      transition: opacity 0.3s;
    }

    .nav-solutions:hover .nav-underline {
      display: block;
      opacity: 1;
    }

    .solutions-overlay {
      display: none;
      position: absolute;
      left: 0;
      top: 40px;
      width: 900px;
      background: #fff;
      box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
      border-radius: 8px;
      padding: 2em;
      z-index: 999;
      min-height: 260px;
    }

    .nav-solutions:hover .solutions-overlay,
    .solutions-overlay.show {
      display: flex;
    }

    .solutions-level1 {
      width: 140px;
      border-right: 1px solid #eee;
      padding-right: 1em;
    }

    .solutions-level1 ul {
      list-style: none;
      padding: 0;
      margin: 0;
      display: flex;
      flex-direction: column;
      gap: 0.5em;
    }

    .solutions-level1 li {
      padding: 0.7em 1.5em;
      cursor: pointer;
      font-weight: bold;
      color: var(--primary);
      border-radius: 4px;
      margin-bottom: 0;
      transition: background 0.2s, color 0.2s;
      white-space: nowrap;
    }

    .solutions-level1 li.active,
    .solutions-level1 li:hover {
      color: var(--accent-hover);
      background: none;
    }

    .solutions-detail-list {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 1em;
      padding-left: 2em;
    }

    .solution-detail-item {
      display: flex;
      align-items: stretch;
      background: #f9f9f9;
      border-radius: 10px;
      overflow: hidden;
      min-height: 110px;
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
      transition: box-shadow 0.2s;
    }

    .solution-detail-img {
      width: 180px;
      height: 110px;
      object-fit: cover;
      flex-shrink: 0;
    }

    .solution-detail-content {
      flex: 1;
      display: flex;
      flex-direction: column;
      justify-content: flex-start;
      padding: 1em 1.2em;
    }

    .solution-detail-title {
      font-size: 1.1em;
      font-weight: bold;
      color: var(--primary);
      align-self: flex-start;
    }

    .solution-detail-desc {
      font-size: 0.98em;
      color: #666;
      align-self: flex-start;
      margin-top: 0;
    }