<style>
.out{
margin: 200px;
transform-style: preserve-3d;
animation: all 3s linear infinite;
transform-origin: 100px;
}
.out>div{
background: radial-gradient(transparent 30%,rgba(0,0,0,0.3) 100%);
height: 200px;
width: 200px;
border-radius: 50%;
position: absolute;
}
.d1{
transform: rotateY(0deg);
}
.d2{
transform: rotateY(120deg);
}
.d3{
transform: rotateY(240deg);
}
@keyframes all {
0%{
transform: rotateY(0deg);
}
100%{
transform: rotateY(360deg);
}
}
</style>
</head>
<body>
<div class="out">
<div class="d1"></div>
<div class="d2"></div>
<div class="d3"></div>
</div>
</body>
</html>