Apply values per media breakpoints. Breakpoints are similar to the breakpoints used in bootstrap css framework. https://getbootstrap.com/docs/4.1/layout/overview/#responsive-breakpoints
example
Container c = Container(
padding: valueFor<EdgeInsetGeometry>(
context,
xs:EdgeInsets.only(left: 25, right: 20),
md:EdgeInsets.only(left: 25, right: 20),
lg:EdgeInsets.only(left: 25, right: 20),
)
);
double num = valueFor<double>(
context,
xs:1,
sm:2,
md:3,
lg:4,
xl:4,
);