body #book{
  
  
  margin: auto;
}
#book{
  
  
  margin:auto;
  
  
  
  
}

#book h1, #book h2 , #book h3, #book h4 {
  
  
}
#book h1 span.number{
  
}
#book p {
  
}
#book #table_of_contents ul li.section,
#book #table_of_contents ul li.subsection{
  
}