.zoom {
     animation-name: zoomInOut;
     animation-duration: 1s;
     animation-timing-function: ease-in-out;
     animation-iteration-count: infinite;
 }

 @keyframes zoomInOut {
     0% {
         transform: scale(1);
     }

     50% {
         transform: scale(1.1);
     }

     100% {
         transform: scale(1);
     }
 }