I need instructions for the Menu component upgrade

[walk-liuyan]

Story background：
when my package.json file 's antd version from 2.12.X upgrade to 3.3.3,
1、 i found menu component the secondary menu is lower than the primary menu 4px？
2、 i found the last menu in the secondary menu floats upward, and the penultimate menu floats downward. in 2.12.x all floats downward。
I would like to get a antd compontns design document～～

Why would I ask that?
In the past, when I used the menu component, I would dynamically calculate the marginBottom of menu. After the upgrade and when the last level menu is opened, the distance of the marginBottom is redundant.
Look at the picture：

END:
You guys helped me decide and calculate distance very friendly but it affected my previous UI.
I would like to get a antd compontns design document～～

[ant-design-bot]

Hello @walk-liuyan, your issue has been closed because it does not conform to our issue requirements. Please use the Issue Helper to create an issue, thank you!

你好 @walk-liuyan，为了能够进行高效沟通，我们对 issue 有一定的格式要求，你的 issue 因为不符合要求而被自动关闭。你可以通过 issue 助手 来创建 issue 以方便我们定位错误。谢谢配合！