Text-based stimulus: It includes a horizontal CSS grid with two explicit columns labeled 100px each, followed by one dashed implicit column labeled by the CSS property grid-auto-columns: 80px but without a numeric width inside the column. Mark grid lines 1, 2, 3, and 4. It places one item between lines 3 and 4. Use the text-based stimulus. A grid defines two explicit 100px columns and grid-auto-columns: 80px. An item is placed at grid-column: 3 / 4. What width is the implicit column that holds it?