Row and Column structures
◦ Current styles (colors, margins, paddings... and the Row and Column headings) are only visible here to be more understandable.
◦ To define the number of Columns, edit the value of the Sass $grid-columns-number var (default: 16).
◦ All content (including new levels of Rows) are necessarily contained in a Column: a row will never have any other content than Columns.
◦ Columns are necessarily containred in a parent Row: a Column cannot exist without a Row.
◦ To not break the Grid structure, only the Rows can receive additional classes to set the dimensions (paddings, height...) and I recommend to do the same about the themes (colors, backgrounds...) and so, in order to get some uniform code, and I recommend to not stylise the Columns.