TASK-24: Cleanup CSS

[r-saba]

Task Description

As a developer, I want to clean up CSS to maintain best practices.

There are a few issues we noticed with the SCSS in the application:

• There are some practices we were using for CSS at the start of the project which we are no longer using, these should be updated everywhere they're used (e.g em for spacing or border-box where not needed).
• When there are multiple of the same custom components, the related SCSS file is imported multiple times. ( In Dev environment), double-check if this affects prod

Acceptance Criteria

• Multiple SCSS files are no longer observed
• Documentation present where necessary

[RGPosadas]

Nice to do, but we don't know if we will have time