fix: tree switcher's background display unexpected in dark theme

components/tree/demo/basic-dark.tsx

@@ -0,0 +1,65 @@
+import React from 'react';
+import { Tree, ConfigProvider, theme } from 'antd';
+import type { DataNode, TreeProps } from 'antd/es/tree';
+
+const { darkAlgorithm } = theme;
+
+const treeData: DataNode[] = [
+  {
+    title: 'parent 1',
+    key: '0-0',
+    children: [
+      {
+        title: 'parent 1-0',
+        key: '0-0-0',
+        disabled: true,
+        children: [
+          {
+            title: 'leaf',
+            key: '0-0-0-0',
+            disableCheckbox: true,
+          },
+          {
+            title: 'leaf',
+            key: '0-0-0-1',
+          },
+        ],
+      },
+      {
+        title: 'parent 1-1',
+        key: '0-0-1',
+        children: [{ title: <span style={{ color: '#1890ff' }}>sss</span>, key: '0-0-1-0' }],
+      },
+    ],
+  },
+];
+
+const App: React.FC = () => {
+  const onSelect: TreeProps['onSelect'] = (selectedKeys, info) => {
+    console.log('selected', selectedKeys, info);
+  };
+
+  const onCheck: TreeProps['onCheck'] = (checkedKeys, info) => {
+    console.log('onCheck', checkedKeys, info);
+  };
+
+  return (
+    <ConfigProvider
+      theme={{
+        algorithm: [darkAlgorithm],
+      }}
+    >
+      <Tree
+        showLine
+        defaultExpandedKeys={['0-0-0', '0-0-1']}
+        defaultSelectedKeys={['0-0-0', '0-0-1']}
+        defaultCheckedKeys={['0-0-0', '0-0-1']}
+        onSelect={onSelect}
+        onCheck={onCheck}
+        treeData={treeData}
+      />
+    </ConfigProvider>
+  );
+};
+
+export default App;

components/tree/index.zh-CN.md

@@ -18,6 +18,7 @@ demo:
 
 <!-- prettier-ignore -->
 <code src="./demo/basic.tsx">基本</code>
+<code src="./demo/basic-dark.tsx">基本-暗色模式</code>
 <code src="./demo/basic-controlled.tsx">受控操作示例</code>
 <code src="./demo/draggable.tsx">拖动示例</code>
 <code src="./demo/dynamic.tsx">异步数据加载</code>

components/tree/style/index.tsx

@@ -347,7 +347,7 @@ export const genBaseStyle = (prefixCls: string, token: TreeToken): CSSObject =>
 
         // ============== Cover Background ==============
         [`${treeCls}-switcher`]: {
-          background: token.colorBgContainer,
+          background: 'transparent',
 
           '&-line-icon': {
             // https://github.com/ant-design/ant-design/issues/32813