Style hierarchy
Styles can be applied to text on several different levels: a selection of text within a row, a row, an indentation level, a column, or the whole document.
Rows can inherit styles from parent rows. For example, a parent row might designate a style for all of its children, or for all of its grandchildren.
In general, more locally-defined styles take precedence over more generally-defined styles. If you have a whole-document style that sets the font size to 16 points, and a row style that sets the font size to 12 points, the row's text will honor the 12-point style. You can check the Style Attributes inspector to find out the priority of styles being applied to the current selection.
Styles that do not conflict will coexist. If you have a whole-document style that sets the text color to red, and a row style that sets the text size to 16 points, that row will display 16-point red text.
All styles acting on the current selection will be displayed in the Style Attributes inspector, in order of their precedence.