Grid by Example

Everything you need to learn CSS Grid Layout

Subgrid on columns and rows

To define a subgrid in both dimensions - columns and rows - use the value subgrid on a grid item of the parent as the value of grid-template-columns and grid-template-rows. The nested grid is now tied to the number of grid tracks and dimensions of the parent grid.

Read the specification | View example as full page

See the Pen Grid by Example 2.1: subgrid columns and rows by rachelandrew (@rachelandrew) on CodePen.