.circle{animation:upDown 1s ease-in-out infinite}.circle:first-child{animation-delay:0s}.circle:nth-child(2){animation-delay:.2s}.circle:nth-child(3){animation-delay:.4s}.circle:nth-child(4){animation-delay:.6s}@keyframes upDown{0%,to{transform:translateY(0)}50%{transform:translateY(-10px)}}