Css editor does not suppport nesting #2123

Describe the bug

The CSS editor currently does not support nested CSS syntax. Valid nested rules are reported as errors and are not parsed correctly.

Link to the blitz that caused the error

https://stackblitz.com/edit/stackblitz-starters-ovqbc6kw?description=HTML/CSS/JS%20Starter&file=script.js,styles.css,index.html&terminalHeight=10&title=Static%20Starter

Steps to reproduce

1. Open the CSS editor.
2. Add a nested rule, for example:

.container {
    color: red;

    .title {
        color: blue;
    }
}

3. Watch highlighted nested selectors.

Expected behavior

The editor should recognize and correctly handle CSS nesting syntax.
CSS Nesting is part of the modern CSS specification and is supported by current versions of major browsers.

Parity with Local

• I have run the project in my local machine and I could not reproduce the issue.

Screenshots

Platform

Browser name  = Chrome
Full version  = 147.0.0.0
Major version = 147
navigator.appName = Netscape
navigator.userAgent = Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.36 OPR/131.0.0.0
performance.memory = {
  "totalJSHeapSize": 58854598,
  "usedJSHeapSize": 51003066,
  "jsHeapSizeLimit": 4294967296
}
Hash = 29a3b5f7

Additional context

No response