navigationBarUnselectedLabelSize property
The size of the text label on unselected items.
If null, the default value depends on the navigationBarIsStyled value.
If it is true, resulting size is 11 dp, coming from the custom
TextStyle in TextTheme FlexColorScheme.m3TextTheme and its overline
text style, which defines the size to 11 dp in accordance to M3 text
styles.
If navigationBarIsStyled is false and all other text theming options
are also null, the default size will depend on ambient text size of
TextTheme.overline as will it other style options. What size this is
will depend on used Typography which may be impacted by locale and
Flutter version, typically it will be 10dp with a very wide letter
spacing.
If size is defined, it overrides the font size on effective label TextStyle on selected item. A fallback value of 11 dp is also applied should the geometry in passed in used TextStyle be missing.
Implementation
final double? navigationBarUnselectedLabelSize;