animate.css/source/attention_seekers/shake.css

@keyframes shake {
	0%, 100% {transform: translateX(0);}
	10%, 30%, 50%, 70%, 90% {transform: translateX(-10px);}
	20%, 40%, 60%, 80% {transform: translateX(10px);}
}

.shake {
	animation-name: shake;
}