rem property
Unit
get
rem
Refers to the CSS rem (root em) unit.
This is used to specify a length relative to the font size of the root element (usually the element). For example, '2.rem' is equal to twice the font size of the root element. If all child elements use rem units, then simply changing the value of the root element will proportionally adjust the values of the children.
Implementation
Unit get rem => Unit.rem(toDouble());