第一种方法：笨方法 不停画圆即可实现。
HTML部分
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JS Bin</title>
</head>
<body>
<div id="YinYang">
<div class="one"></div>
<div class="two"></div>
<div class="three"></div>
<div class="four"></div>
</div>
</body>
</html>
Css部分
body{
background-color: #444;
}
#YinYang{
width:200px;
height: 200px;
border: 1px solid black;
border-radius: 50%;
background: linear-gradient(180deg, rgba(255,255,255,1) 0%, rgba(255,255,255,1) 50%, rgba(0,0,0,1) 51%, rgba(0,0,0,1) 100%);
position: relative;
margin:100px auto;
}
#YinYang > .one{
width: 100px;
height: 100px;
border-radius: 50%;
background: black;
position: absolute;
top:50px;
}
#YinYang > .two {
width:100px;
height: 100px;
background: white;
position: absolute;
top:50px;
left:100px;
border-radius: 50%;
}
#YinYang > .three {
border: 1px solid black;
width:25px;
height:25px;
background: white;
position: absolute;
top:85px;
border-radius:50%;
left:35px;
}
#YinYang > .four{
border: 1px solid black;
width:25px;
height:25px;
background: black;
position: absolute;
top:85px;
border-radius:50%;
left:140px;
}
效果图：
太极.png
第二种方法：利用伪类 before 和 after 。
HTML
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JS Bin</title>
</head>
<body>
<div id="YinYang">
</div>
</body>
</html>
#YinYang {
width: 96px;
height: 48px;
background: #eee;
border-color: red;
border-style: solid;
border-width: 2px 2px 50px 2px;
border-radius: 100%;
position: relative;
}
#YinYang::before {
content: '';
position: absolute;
top: 50%;
left: 0;
background: #eee;
border: 18px solid red;
border-radius: 100%;
width: 12px;
height: 12px;
}
#YinYang::after {
content: '';
position: absolute;
top: 50%;
left: 50%;
background: red;
border: 18px solid #eee;
border-radius:100%;
width: 12px;
height: 12px;
}
