/* IPP-04: shared disclosure controls, focus indication, and hidden panels. */
header .nav-disclosure {
  appearance: none;
  border: 0;
  background: transparent;
  padding: 0;
  margin: 0;
  position: relative;
  color: var(--muted, #5c6074);
  font: inherit;
  line-height: inherit;
  white-space: nowrap;
  cursor: pointer;
}
header .nav-disclosure::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 0;
  height: 2px;
  background: var(--accent, #1f3f77);
  transition: width .2s ease;
}
header .nav-disclosure:hover::after,
header .nav-disclosure:focus-visible::after,
header .nav-disclosure[aria-expanded="true"]::after { width: 100%; }
header a:focus-visible,
header button:focus-visible {
  outline: 3px solid var(--accent, #1f3f77);
  outline-offset: 4px;
  border-radius: 3px;
}
header .submenu[hidden],
header .mobile-submenu[hidden],
header .mobile-nav[hidden] { display: none !important; }
header .nav-item { position: relative; }
header .nav-item.is-open > .submenu {
  visibility: visible;
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
  transition: opacity .2s ease, transform .2s ease;
}
/* Preserve the pointer route across the old 12 px submenu margin. */
header .nav-item.is-open::before {
  content: "";
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  height: 16px;
}
@media (prefers-reduced-motion: reduce) {
  header .nav-disclosure::after,
  header .submenu,
  header .menu-toggle span,
  header .mobile-submenu-toggle { transition: none !important; }
}