/* 顶部导航 */
    .navbar {
      background: #283663;
      color: #fff;
      position: relative;
      z-index: 1000;
    }
    .navbar .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.5rem 1rem;
    }
    .navbar .logo {
      font-size: 1.2rem;
      font-weight: bold;
    }

    /* 桌面端导航 */
    .nav-links {
      list-style: none;
      display: flex;
      margin: 0;
      padding: 0;
    }
    .nav-links li {
      position: relative;
    }
    .nav-links li a {
      display: block;
      padding: 0.5rem 1rem;
      color: #fff;
      text-decoration: none;
    }
    .nav-links li a:hover {
      background: #283663;
    }

    /* 二级菜单 (PC端 hover) */
    .nav-links li ul {
      display: none;
      position: absolute;
      top: 100%;
      left: 0;
      background:#283663;
      list-style: none;
      min-width: 150px;
      margin: 0;
      padding: 0;
      z-index: 1000;
    }
    .nav-links li:hover > ul {
      display: block;
    }
    .nav-links li ul li a {
      padding: 0.5rem 1rem;
      white-space: nowrap;
    }

    /* 小三角图标 */
    .arrow {
      display: inline-block;
      margin-left: 5px;
      border: solid #fff;
      border-width: 0 2px 2px 0;
      padding: 3px;
      transform: rotate(45deg);
      transition: transform 0.3s ease;
    }
    /* PC端 hover 时箭头翻转 */
    .nav-links li:hover > a .arrow {
      transform: rotate(-135deg);
    }

    /* 汉堡按钮 + 抽屉菜单 默认隐藏 */
    .menu-toggle,
    .drawer,
    .overlay {
      display: none;
    }

    /* 移动端适配 */
    @media (max-width: 1024px) {
      /* 隐藏 PC 导航 */
      .nav-links {
        display: none;
      }

      /* 显示汉堡按钮 */
      .menu-toggle {
        display: flex;
        flex-direction: column;
        cursor: pointer;
      }
      .menu-toggle span {
        width: 25px;
        height: 3px;
        background: #fff;
        margin: 4px 0;
        transition: 0.3s;
      }

      /* 抽屉菜单 */
      .drawer {
        display: block;
        position: fixed;
        top: 20;
        left: -250px;
        width: 250px;
        height: 100%;
        background: #283663;
        overflow-y: auto;
        transition: left 0.3s ease;
        z-index: 1100;
        padding-top: 60px;
      }
      .drawer.active {
        left: 0;
      }
      .drawer ul {
        list-style: none;
        margin: 0;
        padding: 0;
      }
      .drawer li a {
        display: block;
        padding: 0.8rem 1rem;
        color: #fff;
        text-decoration: none;
        border-bottom: 1px solid #444;
      }
      .drawer li a:hover {
        background: #69759b;
      }

      /* 抽屉里的子菜单 (折叠式) */
      .drawer li ul {
        display: none;
        background: #283663;
      }
      .drawer li.open > ul {
        display: block;
      }
      .drawer li ul li a {
        padding-left: 2rem;
      }

      /* 移动端箭头旋转效果 */
      .drawer li.open > a .arrow {
        transform: rotate(-135deg);
      }

      /* 遮罩层 */
      .overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0,0,0,0.5);
        z-index: 1000;
      }
      .overlay.active {
        display: block;
      }
    }