/* Fixed nav — hides on scroll down, shows on scroll up */
nav {
  position: fixed !important;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  transition: transform 0.28s ease, box-shadow 0.28s ease;
}
nav.nav-hidden {
  transform: translateY(-100%);
  pointer-events: none;
}
body {
  padding-top: var(--nav-h, 72px);
}
@media (max-width: 768px) {
  body {
    padding-top: var(--nav-h, 96px);
  }
}
@media (prefers-reduced-motion: reduce) {
  nav { transition: none; }
}