Manually control line breaks inside of PressBooks headings when exporting to PDF.

Manual PDF heading breaks in PrinceXML

/*

The following CSS works with PressBooks
PDF Export
http://www.pressbooks.com

Let's say that the Chapter 1 heading is
"The Need for Creative Solutions That Work"

By default, PressBooks outputs this to PDF as...
"The Need for Creative Solutions"
          "That Work"

Here is how to manually control the line breaks
so that it becomes...
       "The Need for"
"Creative Solutions That Work"

*/

div#chapter-1 h2.chapter-title {
  display:block;
  prince-text-replace: " Creative Solutions that Work" "";
}
div#chapter-1 h2.chapter-title:after {
  display:block;
  content: 'Creative Solutions That Work';
  white-space: pre;
}