Tailwind CSS support

[Ibadichan]

Hi! Thanks for the library.

We are using used-styles with Tailwind CSS in our project, and I noticed an issue with the critical CSS generation when classes contain unescaped characters, such as : or []. Examples of such classes include:

• .md:mb-0
• .text-[#000]

Tailwind CSS automatically escapes these classes during the CSS build process, transforming them into:

• .md\:mb-0
• .text-\[#000\]

However, when calling getCriticalStyles, your library cannot locate these classes correctly, as it searches for the unescaped versions (e.g., md:mb-0), while the build files contain their escaped counterparts (e.g., md\:mb-0).

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Steps to Reproduce

1. Clone the repository from used-styles examples and run any example.
2. Simulate a Tailwind-like scenario by adding the class md:mb-0 to a React component.
3. Define the corresponding CSS rule in the main CSS file, e.g., .md\:mb-0 { margin-bottom: 0; }.
4. Observe the result: the class md:mb-0 is not included in the critical styles.

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Suggested Solution

Would it be possible to add support for Tailwind CSS in your library by escaping class names when searching them in the build files? This should resolve the issue.

Thanks.