Update the app UI design

[VictorKabata]

Description

• Update the app typography and color system.

Issue

Changes Made

Screenshots / GIFs

Checklist

• I have tested the changes on both Android, iOS and Desktop platforms.
• I have written unit tests for the new code (if applicable).
• I have updated the project's documentation (if necessary).
• I have checked for any potential code duplications and removed them.
• I have run the Kotlin/Compose Multiplatform Gradle tasks and verified that they were completed successfully.
• I have considered the impact of these changes on the existing codebase.

Additional Notes