The arrow icons are not centered in the use case section of landing page

### 问题描述

The arrow icons are not centered with parent element border, that looks like a bug.

### 重现链接

https://l7.antv.antgroup.com/

### 重现步骤

_No response_

### 预期行为

The icon need centered in that box.

### 平台

- 操作系统: [macOS, Windows, Linux, React Native ...]
- 网页浏览器: [Google Chrome, Safari, Firefox]

### 屏幕截图或视频（可选）


### 补充说明（可选）

_No response_