The grid cells below do not specify any widths, they just naturally space themselves equally and expand to fit the entire row. They’re also equal height by default.
When equal widths aren’t what you want, you can add sizing classes to individual cells. Cells without sizing classes simply divide up the remaining space as normal.
Top-aligned Grid Cells
Vertically-centered Grid Cells
Bottom-aligned Grid Cells
For more info, visit https://css-tricks.com/snippets/css/a-guide-to-flexbox/