html - Is is possible to transition display using CSS?

Something like

#apex1-1{
  width: 100%;
  height: 40px;
  background: rgba(255, 255, 255, 0.8);
}
#apex1-1a{

  display: none;
  transition: display 2s;
}

Instead of just having the element in question just pop up when you set it's display I want it to gradually display.