header {
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

header.scrolled {
  background: rgba(255, 255, 255, 0.95);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

header.scrolled a {
  color: #3a3a3a !important;
  text-shadow: none;
}

.menu-btn {
  width: 3rem;
  height: 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(103, 147, 196, 0.92);
  color: #fff;
  border-radius: 9999px;
  font-size: 1.7rem;
  box-shadow: 0 6px 16px rgba(15, 30, 47, 0.25);
  transition: background 0.25s ease, transform 0.15s ease, box-shadow 0.25s ease;
}

.menu-btn:hover {
  background: #4e759f;
  transform: translateY(-1px);
}

.menu-btn:active {
  transform: translateY(1px);
}

header.scrolled .menu-btn {
  background: #0f1e2f;
  box-shadow: 0 4px 12px rgba(15, 30, 47, 0.2);
}