.flicker {
  -webkit-animation: flicker 4s infinite;}
@keyframes flicker {
  0% {opacity:1;}
  9% {opacity:0.3;}
  10% {opacity:.5;}
  13% {opacity:0.3;}
  20% {opacity:.5;}
  25% {opacity:1;}}
 @-webkit-keyframes flicker {
  0% {opacity:1;}
  9% {opacity:0.3;}
  10% {opacity:.5;}
  13% {opacity:0.3;}
  20% {opacity:.5;}
  25% {opacity:1;}
}