style: Adjust less style in global.less to avoid error tips in WebStorm and VS Code

[raoanqi]

Types of changes

• New feature
• Bug fix
• Enhancement
• Component style change
• Typescript definition change
• Documentation change
• Coding style change
• Refactoring
• Test cases
• Continuous integration
• Breaking change
• Others

Background and context

If you open this project with the latest WebStorm(version: 2023.2.4) or VS Code(version: 1.83.1), there are error tips in global.less file. This won't impact launch project, but I adjust style to avoid this error tips appear in IDE or editor.

WebStorm screenshot:

VS Code screenshot:

Solution

How is the change tested?

Changelog

Component	Changelog(CN)	Changelog(EN)	Related issues

Checklist:

• Test suite passes (npm run test)
• Provide changelog for relevant changes (e.g. bug fixes and new features) if applicable.
• Changes are submitted to the appropriate branch (e.g. features should be submitted to feature branch and others
  should be submitted to main branch)

Other information