[Font] group
Used to specify a font in the edit field.
[Proportional font] box
Used to specify a font for normal text and headings.
[Fixed Font] box
Used to specify a font for text that uses a preformatted fixed font.
[Font Size] box
Used to specify a font size.
The type and size of a font specified here are the settings in the edit field of Homepage Builder. Thus, even though you change a font here, there is no effect in the browser display, since the browser has its own font settings.