Learning-component & block-quote dark mode

### Project

webcomponents (UX / frontend)

### What would you like to see?

<img width="1660" height="1305" alt="Image" src="https://github.com/user-attachments/assets/8fd10baf-35f1-44f7-80eb-ca901892d563" />

These components should be reviewed for dark mode as they are text heavy and the white background can be jarring for dark mode users

### Why would this be useful?

_No response_