elementui el-tree节点悬浮和点击时高亮显示

树形组件背景颜色的修改，点击节点背景颜色修改,悬浮时背景颜色修改–参考博客

<div class="layout">
    <el-scrollbar style="height:100%">
       <el-tree
       :props="defaultProps"
       :load="loadNode"
       lazy
       accordion
       node-key="id"
       @node-click="handleNodeClick"
       :default-expanded-keys="dafaultShowNodes"
       style="height: 100%;"
      >
      </el-tree>
   </el-scrollbar>
</div>

/* 点击后的当前节点的样式 */
.el-tree-node.is-current > .el-tree-node__content {
  background: rgb(48, 65, 86);
  color: rgb(64, 158, 255);
}
/* 点击后的当前节点的子节点的背景颜色 */
.el-tree>.el-tree-node.is-current {
  background: #1f2d3d;
}
/* 鼠标悬浮的当前节点  */
.el-tree-node__content:hover {
  background: #3e4b5a!important;
}