Once you include flex-grids.min.css in your html file you are all set to use flex-grids, now just you need to add some classes.. flex-grids is a rows and columns grid-based, each row represents a grid ...

In 4.2.Flex Item Margins and Paddings, the Flexbox spec says that flex item padding percentage values should be resolved against the inline size of the containing block — the containing block being ...