Percentage height and width

Elements with widths or heights defined with percentage (%) will shrink or expand relative to its container’s height or width. This container can be a Screen, a Dynamic Panel, or a Table.
Percentage example

You’ll find this property by looking to the Properties palette, and then to the Size section. Click on the drop-down next to the width or height, and change it from “px” to “%”.
Percentage dropdown

Once you change an element’s height or width to percentage (%) it will be responsive to the simulation window’s height or width.

Note: Simulation settings must be set to expand to the browser width. You can specify this in simulation settings, or in the simulation window.

Simulation setting