This document provides an overview of the utility classes.
The font classes follow the format .xx-{size}, or .xx-{style} where .xx are the initials for the class, for example for font size .xx-{style} would be .fs-{style}.
{size} represents the desired size in rem and {style} is the desired style. For example if font size is 2rem then .xx-{size} would be .fs-2rem. For a style example if we want to have a display flex then for .xx the initials of display are kept (d) and for style = flex. It would be .d-flex