Why Salesforce interfaces need mobile-first thinking.

Desktop layouts do not simply shrink.

A dense desktop table, multi-column form or complex navigation often needs a different arrangement on mobile. Responsive design is about preserving the important task.

Define the collapse rules.

Decide early which columns disappear, which cards stack, how navigation changes and how controls behave.

Test the real workflow.

Responsive testing should cover the actions users actually perform: finding records, submitting forms, navigating pages and reviewing information.

Make mobile part of the build.

When responsive behavior is considered during component architecture, it becomes much easier to produce interfaces that work consistently across screen sizes.