#nav-toggle {
  box-shadow: 0 0 12px rgba(0,0,0,0.33);
  transition-duration: 200ms;
  transition-property: box-shadow;
}


#nav-toggle:hover {
  box-shadow: 0 0 6px rgba(0,0,0,0.55);
}

#nav-toggle:active {
  box-shadow: 0 0 4px rgba(0,0,0,0.65);
}