/* Nav separator: above Introduction (1st item) — separates site title from content */
.md-nav--primary > .md-nav__list > .md-nav__item:nth-child(1) {
  border-top: 1px solid var(--md-default-fg-color--lightest);
  margin-top: 0.6em;
  padding-top: 0.6em;
}

/* Horizontal rule below "Table of contents" label, above first entry */
.md-nav--secondary > .md-nav__title {
  border-bottom: 1px solid var(--md-default-fg-color--lightest);
  padding-bottom: 0.4em;
  margin-bottom: 0.4em;
}

/* Nav separator: above Building Blocks (7th item) — separates paper body from appendices */
.md-nav--primary > .md-nav__list > .md-nav__item:nth-child(7) {
  border-top: 1px solid var(--md-default-fg-color--lightest);
  margin-top: 0.6em;
  padding-top: 0.6em;
}