[pro:layout] pro-layout中type为‘header’时，菜单样式存在问题

[Darma1106]

• I have searched the issues of this repository and believe that this is not a duplicate.

Reproduction link

https://idux.site/pro/layout/zh

Steps to reproduce

1.访问官网文档【pro-layout】

2.在【布局类型】中选择【header】

3.选择tab

What is expected?

菜单样式排列正常，根据对应样式类为【&-vertical】，推测应该为垂直排列。

What is actually happening?

菜单横向排列且比较混乱

【header.less】中【&-vertical】 存在不必要的flex

Environment Info

官网文档

[idux-bot]

Translation of this issue:

[Pro: Layout] When Type is ‘header’ in Pro-Layout, there is a problem with the menu style

• I have searched the [issues] (https://github.com/iduxfe/idux/isSues) of this repository that this is not a duplicate.

REPRODUCTION LINK

[https://idux.site/pro/layout/zh]

STEPS To Reproduce

1. Visit the official website document [Pro-layout]

2. Select [Header] in [layout type]

3. Select TAB

What is exfected?

The menu style arrangement is normal. According to the corresponding style class, it is [& -Vertical]. It is speculated that it should be vertically arranged.

What is actually happy?

The menu is arranged horizontally and confusing

[Header.less] [& -Vertical] There is an unnecessary Flex

ENVIRONMENT Info

官网文档