body
{
	font-family: monospace;
}

.tourne
{
	height: 100px;
	width: 100px;
	margin: 50px;
	background-color: red;
	position: relative;
	animation-name: tourne;
	animation-duration: 2s;
	animation-iteration-count: infinite;
	animation-direction: alternate;
	animation-timing-function: linear;
}

@keyframes tourne
{
	0%
	{
		transform: rotate(0deg);
	}

	25%
	{
		transform: rotate(90deg);
	}

	50%
	{
		transform: rotate(180deg);
	}

	75%
	{
		transform: rotate(270deg);
	}

	100%
	{
		transform: rotate(360deg);
		background-color: yellow;
	}
}