The syntax highlighting for CSS is not working properly inside multiline strings

[guilhermenevesxyz]

This issue occurs when all the extensions are disabled.

Version info

• VS Code Version: 1.65.2
• OS Version: Windows 11 Pro Education 21H2

Steps to Reproduce

1. Create a CSS file;
2. Open it in VS Code;
3. Use line-breaking syntax to separate a string into multiple lines (see example below);

Image illustrating the issue

See that after using that syntax for breaking the line, the syntax highlighting becomes messed up.

Note that this does not happen in other languages. Here is an example in C:

[aeschli]

For CSS, we use the grammar from https://github.com/atom/language-css.
The issue has already been reported there: atom/language-css#181
Closing as duplicate.