CSS code within the `<style>` block not having syntax highlighting

## Description

I found that CSS code inside the `` block isn't getting syntax highlighting. This issue can be seen in both coding challenges and review / lecture transcripts.

- Coding challenge: FSD -> Basic CSS -> Design a Cafe Menu -> Step 12
<details>
<summary>Scrernshot</summary>

<img width="400" alt="Image" src="https://github.com/user-attachments/assets/d5042b88-0475-453d-9764-792de837f0c2" />
</details>
- Lecture transcript: FSD -> Basic CSS -> What is CSS -> How Do Width and Height Work?
<details>
<summary>Scrernshot</summary>

<img width="397" alt="Image" src="https://github.com/user-attachments/assets/cc974d6f-522c-40f5-bc78-4c2f5b0b0d69" />

</details>