.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--zr-bg);
  border-bottom: 1px solid var(--zr-rule);
  padding: 1.25rem var(--zr-gutter);
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem 2rem;
}

.masthead {
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.masthead__wordmark {
  font-family: var(--zr-font-display);
  font-weight: 700;
  font-size: clamp(1.25rem, 1.5vw + 0.75rem, 1.75rem);
  letter-spacing: -0.01em;
}

.masthead__tld {
  color: var(--zr-muted);
}

.masthead__meta {
  display: none;
  font-family: var(--zr-font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--zr-muted);
  gap: 1rem;
}

.masthead__meta span + span::before {
  content: "/";
  margin-right: 1rem;
  color: var(--zr-rule);
}

@media (min-width: 900px) {
  .masthead__meta {
    display: flex;
  }
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.site-nav__toggle {
  background: none;
  border: 1px solid var(--zr-rule);
  color: var(--zr-text);
  font-family: var(--zr-font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  padding: 0.5rem 0.875rem;
  cursor: pointer;
}

.site-nav__list {
  display: none;
  font-family: var(--zr-font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.03em;
}

.site-nav__list a {
  display: block;
  padding-block: 0.35em;
  border-bottom: 1px solid transparent;
  transition: border-color 0.15s var(--zr-ease), color 0.15s var(--zr-ease);
}

.site-nav__list a:hover,
.site-nav__list a:focus-visible {
  color: var(--zr-accent);
  border-color: var(--zr-accent);
}

.site-nav__list.is-open {
  display: flex;
  flex-direction: column;
  position: absolute;
  inset: 100% 0 auto 0;
  background: var(--zr-bg);
  border-bottom: 1px solid var(--zr-rule);
  padding: 1rem var(--zr-gutter) 1.5rem;
  gap: 0.25rem;
}

@media (min-width: 700px) {
  .site-nav__toggle {
    display: none;
  }

  .site-nav__list {
    display: flex;
    flex-direction: row;
    gap: 1.75rem;
    position: static;
    padding: 0;
    border: 0;
    background: none;
  }
}

/* Always visible regardless of mobile/desktop nav state -- the whole point
   is a subscribe entry point that isn't buried at the bottom of the
   homepage or inside the collapsed mobile menu. */
.nav-subscribe {
  position: relative;
}

.nav-subscribe__toggle {
  background: none;
  border: 1px solid var(--zr-accent);
  color: var(--zr-accent);
  font-family: var(--zr-font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.5rem 0.875rem;
  cursor: pointer;
  transition: background-color 0.15s var(--zr-ease), color 0.15s var(--zr-ease);
}

.nav-subscribe__toggle:hover,
.nav-subscribe__toggle:focus-visible {
  background: var(--zr-accent);
  color: var(--zr-bg);
}

.nav-subscribe__panel {
  display: none;
}

.nav-subscribe__panel.is-open {
  display: block;
  position: absolute;
  top: calc(100% + 0.75rem);
  right: 0;
  width: min(22rem, calc(100vw - 2 * var(--zr-gutter)));
  background: var(--zr-bg);
  border: 1px solid var(--zr-rule);
  padding: 1.25rem;
  z-index: 20;
}