.fadein-header {
  background-color: transparent;
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.fadein-header.is-scrolled {
  background: rgba(7, 7, 16, 0.9);
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}