I have a site with two rows of gallery cards. The top row contains four cards and the bottom row contains three cards. I want each of the three cards in the bottom row to be the same size as each of the four cards in the top row with a blank spot on the right side of the bottom row. I don't want the three bottom row cards to be wider so they take up the same width as the row above it. If I add a spacer card it forces the third button below the other two. The spacer works if it's added to a row with two cards. How can I get it to work with a row containing three cards? Can I edit the width of the spacer to accommodate three cards?