I am endlessly confused by the formatting of the default style sheet, particularly that it indents Subchapter titles further right than Section titles. So I'm trying to change the appearance of Subchapter titles, to make them look like Chapter titles (and I'll make the Subchapter titles italic to distinguish them from Chapter titles.)

I understand how to change the size of Subchapter titles, and how to remove the dingbat, but I can't figure out how to remove the indentation? So in this example, "Content" is a Section-title, and "Sampling" is a Subchapter-title, but the indentation looks misleading to me. How to remove the indentation?