.heartbeat {
	width: 500px;
	height: 100px;
/*	border: 2px solid green;*/
	background-color: transparent;
	position: relative;
	margin-left: 3cm;
}

	.heartbeat:after {
		content: "";
		position: absolute;
		left: 0;
		top: 0;
		right: 0;
		bottom: 0;
		background: linear-gradient( to right, white 0%, white 10%, rgba(0, 0, 0, 0) 100% );
		background-repeat: repeat-x;
		background-size: 130% 100%;
		background-position: 0 0;
		animation: graph 3s linear infinite;
	}

@keyframes graph {
	100% {
		background-position: 600px 0;
	}
}