[AC-4549] fix: correct markdown css selectors (#403)

## Changes
- 

ticket: [AC-4549]

## Additional Notes
- 

## Checklist
Before requesting a code review, please check the following:
- [x] **[Required]** CI has passed all checks.
- [x] **[Required]** A self-review has been conducted to ensure there
are no minor mistakes.
- [x] **[Required]** Unnecessary comments/debugging code have been
removed.
- [x] **[Required]** All requirements specified in the ticket have been
accurately implemented.
- [x] Ensure the ticket has been updated with the sprint, status, and
story points.


[AC-4549]:
https://sendbird.atlassian.net/browse/AC-4549?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: bang9