Grid width in list item

While trying to put text in two columns (one aligned left and the other aligned to the right) in the same row in a list item, I realized that the grid doesn’t fill the full width of the list item. Instead, it just fills the width of the content in that row.

Is there a way to have the grid fill all the width available in the list item?

Apply some css to remove the padding/margin of the involved elements?