@keyframes can { 0% { transform: translateY(0) } #{$step * 4} { transform: translateY(0); opacity: 1; } code example

Example: css keyframes animation

//css keyframes
#image{
	  width: 100px;
	  height: 100px;
	  background-color: red;
	  position: relative;
	  animation: monFrame 5s linear 2s infinite alternate;

	}
	@keyframes monFrame {
	  0%   {left:0px; top:0px;}
	  25%  {left:500px; top:0px;}
	  50%  {left:500px; top:500px;}
	  75%  {left:0px; top:500px;}
	  100% {left:0px; top:0px;}
     }