RapidWeaver Stacks add-on info:

TextFit Stack
The TextFit Stack will adjust the size of the text to the available width of the surrounding Stack.

• Use TextFit Stack when you don't want to add a fixed font size in pixels but want the text to take up the container width.
• Make text lines with different number of words take up exactly same width.

Special features:
Option to add custom css to the TextFit Stack and a user defined breakpoint.

Keywords:
RapidWeaver, stacks, responsive, text, headline, scale

RapidWeaver Community Addons:
https://rapidweavercommunity.com/addons/stacks/textfit-stack