body { 
  margin: 0; 
  padding:0; 
  margin: 2em auto; 
  text-align: justify;
} 

#main {
  columns: 2           
}
.spanner { 
  column-span: all; 
}

#main > section > h1 {
  font-size: 13pt;
}
#main > section > section > h1 {
  font-size: 11pt;
}

code {
  font-size: 9pt; 
}
pre {
  font-size: 8pt; 
}