.helper-menu { 
  -webkit-transition: opacity 0.5s ease-in-out; 
  -moz-transition: opacity 0.5s ease-in-out; 
  -o-transition: opacity 0.5s ease-in-out; 
  -ms-transition: opacity 0.5s ease-in-out; 
  transition: opacity 0.5s ease-in-out; 
  display:inline; 
} 