Headings, categories and footer appears with weird css styles from WordPress

Hi sir:

https://polifinus.com/

Since Sunday we are experiencing a weird issue in our site. If you check the url I attached you, looks like the problem comes from the new WordPress version and the Newspaper theme wich does not clean the css coming from Gutenberg editor:

✅ Main culprit: the WordPress core (block editor)

the Newspaper theme, which doesn’t properly override or disable it.

🧠 Why?
Since WordPress version 5.9 (and especially from 6.1 onwards), the block editor (Gutenberg) automatically injects CSS variables into :root and adds classes like .has-white-background-color, .has-black-border-color, .has-shadow–outlined, etc.

This is part of the global styles system from the block editor—even if you haven’t configured it intentionally.

🔍 What does the Newspaper theme do about it?

Newspaper doesn’t block these Gutenberg global styles like other themes do (for example, by disabling theme.json or the global style system).

It also doesn’t reset or sanitize the CSS to prevent those styles from leaking into the frontend, especially if you’re using custom HTML or manual templates.

As a result, you end up with styles that are invisible in the editor, but visibly affect the live site.

🧩 How can I be sure?

Because in the raw HTML of the page, I found this key variable:

–wp–preset–shadow–outlined: 6px 6px 0px -3px rgba(255, 255, 255, 1), 6px 6px rgba(0, 0, 0, 1);