Breakpoint classes

By default, the columns in HubSpot stack vertically at a viewport width of 767px and lower. With Act Theme you can change that. You can add one of the following classes to a group, and its DIRECT child columns will be forced to stack at a different viewport, or even to never stack:

large-stack Direct child columns will stack vertically at a viewpot width of 1079px and lower.
medium-stack Direct child columns will stack vertically at a viewpot width of 890px and lower.
smedium-stack
Default (767px). This class is automatically added to your columns, if no other stack class is set. You don't need to add this class to any element.
small-stack Direct child columns will stack vertically only at a viewpot width of 479px and lower.
tiny-stack Direct child columns will stack vertically only at a viewpot width of 320px and lower.
never-stack Direct child columns will never stack vertically, no matter of the viewport size.

Please read the helper classes article to learn how to apply basic styles (text-align, margin and padding) to the same element, at different breakpoints, and only using Act Theme's classes.