The correct way to design the FlexCard to meet this requirement is to create two states, one for mobile devices and another for non-mobile devices. States allow the designer to define different layouts and behaviors for the same FlexCard based on conditions. The width of the fields can be adjusted for each state using the Size property. Enabling the Responsive feature on the field elements would not change their width, but only their alignment. Enabling the Mobile-First feature in FlexCard settings would not affect the width of the fields, but only the order in which they are displayed. Creating two FlexCards, one for mobile devices and another for non-mobile devices, would create redundant code and maintenance issues.