太阳系主要利用定位，伪元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
* {
padding: 0;
margin: 0;
} html, body {
width: 100%;
height: 100%;
overflow: hidden;
} body {
background-color: #000;
} .sun {
width: 80px;
height: 80px;
border-radius: 50%;
position: absolute;
top: 50%;
left: 50%;
margin-left: -40px;
margin-top: -40px;
background-color: orange;
box-shadow: 0px 0px 30px 2px yellow;
} .earth {
width: 300px;
height: 300px;
border-radius: 50%;
position: absolute;
top: 50%;
left: 50%;
margin-left: -150px;
margin-top: -150px;
border: 1px solid #fff;
animation: gun 10s infinite linear;
} .earth::before {
content: "";
position: absolute;
width: 40px;
height: 40px;
top: 50%;
margin-top: -20px;
left: -20px;
border-radius: 50%;
background-color: blue;
} .moon {
position: absolute;
width: 100px;
height: 100px;
top: 50%;
margin-top: -50px;
left: -50px;
border-radius: 50%;
/*border: 1px solid #fff;*/
animation: gun 2.5s infinite linear;
} .moon:before {
content: "";
position: absolute;
width: 18px;
height: 18px;
top: 50%;
margin-top: -9px;
left: -9px;
border-radius: 50%;
background-color: silver;
} .mars {
width: 460px;
height: 460px;
border-radius: 50%;
position: absolute;
top: 50%;
left: 50%;
margin-left: -230px;
margin-top: -230px;
border: 1px solid #fff;
animation: gun 15s infinite linear;
} .mars::before {
content: "";
position: absolute;
width: 50px;
height: 50px;
top: 50%;
margin-top: -25px;
left: -25px;
border-radius: 50%;
background-color: orange;
} .venus {
width: 600px;
height: 600px;
border-radius: 50%;
position: absolute;
top: 50%;
left: 50%;
margin-left: -300px;
margin-top: -300px;
border: 1px solid #fff;
animation: gun 20s infinite linear;
} .venus::before {
content: "";
position: absolute;
width: 60px;
height: 60px;
top: 50%;
margin-top: -30px;
left: -30px;
border-radius: 50%;
background-color: silver;
} @keyframes gun {
0% {
transform: rotate(0deg);
}
100% {
transform: rotate(360deg);
}
}
</style>
</head>
<body>
<div class="sun"></div>
<div class="earth">
<div class="moon"></div>
</div>
<div class="mars"></div>
<div class="venus"></div>
</body>
</html>
参考资料：cssRules js操作cssRules