http://jensimmons.com/presentation/progressing-our-layouts
https://drafts.csswg.org/css-conditional-3/#at-supports
https://www.sitepoint.com/building-trello-layout-css-grid-flexbox/
So there is your choice. Do you want to let your content control the way it is displayed, on a row by row or column by column basis? That’s flexbox.
Or, do you want to define a grid, and either allow items to be auto-placed into the cells defined by that grid, or control their positioning using line-based positioning or grid template areas. That’s grid.