HubSpot's COS modules work on a flexible grid that automatically adjusts their proportions to fit a viewer's screen dimensions. This "responsive" system relies on percentage widths and heights to make a smooth transition between devices. When a module, column, or wrapper is set to use fixed widths or heights this responsiveness is broken and different screen sizes are no longer able to fluidly adjust the size of your content to fit the viewer's environment. As a best practice, to prevent your layout from breaking on mobile devices, any styling on your COS pages for height and width attributes should be done with min/max width in percentage format.
Last updated: July 28, 2016