refactor: update Sass modules to use @use instead of @import

[ThanishaDewangan]

Description

The codebase currently uses deprecated Sass @import statements which will be removed in Dart Sass 3.0.0. We need to update these to use the modern @use syntax.

Current Behavior

• Sass files use deprecated @import statements
• Mixins and variables are globally available without namespacing
• Extend statements may fail if placeholders aren't found
• Storybook shows deprecation warnings

Expected Behavior

• All Sass files should use @use instead of @import
• Mixins and variables should be properly namespaced
• Extend statements should be made optional with !optional flag
• No deprecation warnings in Storybook

[vtushar06]

Hi @ThanishaDewangan 👋
I’d like to help with this Sass refactor. Could you please let me know if this issue is still open for contribution or if there are remaining files I can work on?

Thanks!