body {
         background-color: #2596be;
      }
#pendel aside {
	top: 100px;
	left: -130px;
	background: #6e6e6e;
	transform-origin: center -100px;
	rotate: 30deg;
	animation: pendel 1s infinite alternate ease-in-out;
}
@keyframes pendel {
	to {
		rotate: -30deg;
	}
}
section {
	margin-right: 0em;
	position: relative;
	width: 300px;
}
section:after,
aside,
.zentrum:before {
	border-radius: 50%;
	position: absolute;
}