- [x] I have searched the [issues](https://github.com/vueComponent/ant-design-vue/issues) of this repository and believe that this is not a duplicate. ### Version 3.3.0-beta.2 ### Environment Vue 3.2.37 ### Reproduction link [](https://codesandbox.io/s/recursing-fog-w7meh3) ### Steps to reproduce bordered size="small" ### What is expected? 展开按钮居中 ### What is actually happening? 样式不正确 <!-- generated by issue-helper. DO NOT REMOVE -->
