html {
  height: 100%;
  width: 100%;
  text-align: center;
  background-color: #efefef;
}

.item {
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 8em;
  position: fixed;  
}

#hey {
  cursor: pointer;
}




@-webkit-keyframes bounce {
    0%, 20%, 50%, 80%, 100% {-webkit-transform: translateY(0);}
    40% {-webkit-transform: translateY(-30px) }
    60% {-webkit-transform: translateY(-20px);}
} 
@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {transform: translateY(0);}
    40% {transform: translateY(-30px);}
    60% {transform: translateY(-20px);}
} 


.bounce {
    -webkit-animation-duration: 1s;
    animation-duration: 1s;
    -webkit-animation-name: bounce;
    animation-name: bounce;
    text-align: center;
  width: 100%;
  height:100%;
}