.flex {
  display:flex;
  justify-content:flex-start;
  flex-wrap:wrap;
}

.flex > DIV {
  margin:2px;
  background:#0c6c66;
  border:1px solid #0c6c66;
  font-size:24pt;
}

.flex > DIV > A {
  display:block;
  padding:25px;
}

.flex > DIV:hover {
   animation:scaling 0.2s;
}

/* animation keyframes */
@keyframes scaling {
   0% { transform:scale3d( 1, 1, 1 ); }
   25% { transform:scale3d( 0.98, 0.98, 0.98 ) rotate(5deg); }
   50% { transform:scale3d( 0.95, 0.95, 0.95 ) rotate(10deg); }
   75% { transform:scale3d( 0.98, 0.98, 0.98 ) rotate(5deg); }
   100% { transform:scale3d( 1, 1, 1 ); }
}