[system2]

You can't modify this without touching html. Just create a div and assign class so you only modify CSS later.

[ok123456]

What would stop it from being styled by CSS in the same way? You could use it for semantic markup.

[system2]

It would be messy. If <center> element is used somewhere else then you will have to find its parent classes. If they don't have proper parent div classes or <center> used in many places then you will have to individually target <center> elements like div > div > div > center and another one div > div > div > div > center.

You can override center too but why would you try that instead of creating a class for a div and addressing it properly. Classless elements cause long-term issues when modified with CSS.