[css-grid] New grid-template-columns keyword to hide column cells

[woody-li]

Currently, for table elements, we have colgroup and col to control column styles.
<col> accepts visibility CSS property to controls column cells not being rendered.

But there's no way to implement the same behavior in grid layout.
We have to hide the cells one by one in a column.

Proposal

A new keyword, such as hidden for grid-template-columns, controls column cells not being rendered.
Such as grid-template-columns: 200px minmax(100px, auto) hidden 50px to hide cells at the third column.

Specification

The grid-template-columns CSS property defines the line names and track sizing functions of the grid columns.

So I think hide and skip column cells render is fit to its function.

Puzzled

I've no idea how to distinguish the behavior between 0 and hidden.