How can you do global changes within pages

Having every single line be its own grid is really tedious.  Surely there must be a way to treat the items on a page as a single entity.  I am creating an online poetry journal.  So, for example, each line of a poem is a hard return–which BoldGrid turns into separate grids.  I want to change the background color for the pages in one fell swoop–not a hundred times, once per line.  Ditto for changing the fonts.  There simply has to be a way to make this possible.  — P.S. Your documentation is also not straightforward.  It took me hours to figure out how to nest pages in drop down menus, even with an hour long phone call.  And even this form is not user friendly.  I have no idea what “tag” is supposed to mean or how my question relates to these headings.