THPDFHTMLImporter.Margin
Page margin in points applied to every side when HTML content is rendered
property Margin: Single read FMargin write FMargin;
The unit is HPDFHTMLImport; the default is 72 points, and the content width of each page is the page width minus twice this margin
The cursor starts at the margin after BeginDoc and after every automatic page break
RenderHTML and RenderHTML5 both honour this setting