navin-postfix.css has content from navin-prefix.css

The content of navin-postfix.css has css that refers to the preface zone:

/* Preface */
#section-content .zone-wrapper #zone-preface .region-inner {
  padding: 20px;
}
#zone-preface .block .content {
  color: #868686;
}
#zone-preface .block .content strong {
  color: #414141;
}
/* Hide on interior pages */
.not-front #zone-preface-wrapper {
  display: none;
}

I couldn't figure out why postfix blocks were displaying but prefix blocks were not. Both say "display: none" but in postfix it refers to preface.

btw, is there a reason that Navin has chosen to not display the preface zone?