title_body: How can I prevent a widowed/orphaned header?
upvoted_answer: According to this blog article, you should use the display: inline-block property on  a div selector that encloses your header and paragraph.
  
  
  
  Here is an excerpt from the said article:
  
  
    If you set the display property for a div to be inline-block,
    iBooks will display the contents of the entire div together on a
    single page, skipping to a new page if necessary, unless the entire
    div can't fit on a page by itself, in which case it will be divided
    across pages.
    
    It's simple and very powerful: div {display: inline-block}
    
    Here's a short document with no inline-block display. Notice how the
    header is separated from the paragraph that follows it, and even how a
    bit of the background bleeds through to the following page. Icks. The
    image and caption are likewise separated. Terrible!
    
    
    
    
    
    Here's the exact same document with one div enclosing the header and
    paragraph and second div enclosing the image and caption. Both
    divs were set to display:inline-block. The result? Goodbye widows
    and orphans:
    
    
    
    
    
    Where can you use this? As shown here, if you have a series of
    illustrations with captions, use inline-block to keep the caption
    right under the illustration.
    
    If you want a header to never appear alone at the bottom of the page,
    but always be followed by at least one paragraph, just enclose the
    header and the paragraph in an inline-block div.
  
  
  
  
  The article that I have linked also contains two epub files that can be used as a reference for these examples.