/* ==========================================================================
   ARIA — Navigation

   Single frosted-glass navigation bar with ARIA branding,
   section links, and CTA button. Apple design tokens.
   ========================================================================== */

/* ── Navigation Bar ── */
.sub-nav-frosted {
  background: rgba(245, 245, 247, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  height: var(--subnav-height);                  /* 52px */
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 999;
  display: flex;
  align-items: center;
  padding: 0 24px;
  border-bottom: 1px solid var(--apple-divider-soft);
}

.sub-nav__title {
  font-family: var(--font-display);
  font-size: var(--text-tagline);                /* 21px */
  font-weight: var(--weight-semibold);
  line-height: var(--leading-tagline);
  letter-spacing: var(--tracking-tagline);
  color: var(--apple-ink);
  margin-right: 32px;
  white-space: nowrap;
}

.sub-nav__links {
  display: flex;
  gap: 12px;
  flex: 1;
  overflow-x: auto;
  scrollbar-width: none;
}

.sub-nav__links::-webkit-scrollbar {
  display: none;
}

.sub-nav__link {
  font-family: var(--font-body);
  font-size: var(--text-button-utility);         /* 14px */
  font-weight: var(--weight-regular);
  line-height: var(--leading-caption-strong);
  letter-spacing: var(--tracking-caption);
  color: var(--apple-ink-muted-80);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: var(--radius-xs);
  transition: color 0.2s ease, background 0.2s ease;
  white-space: nowrap;
}

.sub-nav__link:hover {
  color: var(--apple-ink);
  background: rgba(0, 0, 0, 0.04);
}

.sub-nav__link:active {
  transform: scale(0.95);
}

.sub-nav__link.active {
  color: var(--apple-primary);
  font-weight: var(--weight-semibold);
}

.sub-nav__link:focus-visible {
  outline: 2px solid var(--apple-primary-focus);
  outline-offset: 2px;
}

/* CTA button — Apple pill CTA
   TEMPORARY: subagent C will replace .sub-nav__cta with the floating pill
   header. This rule is kept as a fallback but its visual weight is reduced
   so the upcoming pill will dominate. */
.sub-nav__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  color: var(--apple-primary);
  font-family: var(--font-body);
  font-size: var(--text-button-utility);
  font-weight: var(--weight-regular);
  letter-spacing: var(--tracking-caption);
  border: 1px solid var(--apple-primary);
  border-radius: var(--radius-pill);              /* 9999px pill */
  padding: 6px 14px;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease, color 0.2s ease;
  text-decoration: none;
  white-space: nowrap;
  margin-left: auto;
  opacity: 0.65;
}

.sub-nav__cta:hover {
  background: rgba(0, 102, 204, 0.06);
  color: var(--apple-primary);
  opacity: 1;
}

.sub-nav__cta:active {
  transform: scale(0.95);
}

.sub-nav__cta:focus-visible {
  outline: 2px solid var(--mint);
  outline-offset: 2px;
}

/* ── Mobile hamburger ── */
.nav-hamburger {
  display: none;
  background: none;
  border: none;
  color: var(--apple-ink);
  cursor: pointer;
  padding: 8px;
}

.nav-hamburger-line {
  display: block;
  width: 18px;
  height: 1.5px;
  background: var(--apple-ink);
  margin: 4px 0;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

/* .main-content has no top offset — the header is a side rail
   (.app-header, header-pill.css), not a fixed top bar, so content
   should start flush with the viewport top. (Previously offset by
   --subnav-height for a top pill nav that no longer exists; that
   left a gap above .tile--hero exposing the html background.) */