CSS3绘制旋转的太极图案
实现步骤：
基础HTML：
<div class="box-taiji">
<div class="circle-01"></div>
<div class="circle-02"></div>
</div>
步骤一：
.box-taiji {width:400px;height:400px;position:relative;margin:50px auto;border-radius:400px;background-color:#000;box-shadow:0 0 50px rgba(0,0,0,.8);}
画一个宽高为400px的圆，加上阴影。
步骤二：
.box-taiji {width:400px;height:400px;position:relative;margin:50px auto;border-radius:400px;background-color:#000;box-shadow:0 0 50px rgba(0,0,0,.8);}
.box-taiji:before,
.box-taiji:after {width:200px;height:400px;position:absolute;top:0;display:block;content:"";}
.box-taiji:before {left:0;border-radius:200px 0 0 200px;background-color:#000;}
.box-taiji:after {right:0;border-radius:0 200px 200px 0;background-color:#fff;}
利用伪类实现左右两个半圆，一黑一白。宽为200px，高为400px;
步骤三：
.box-taiji {width:400px;height:400px;position:relative;margin:50px auto;border-radius:400px;background-color:#000;box-shadow:0 0 50px rgba(0,0,0,.8);}
.box-taiji:before,
.box-taiji:after {width:200px;height:400px;position:absolute;top:0;display:block;content:"";}
.box-taiji:before {left:0;border-radius:200px 0 0 200px;background-color:#000;}
.box-taiji:after {right:0;border-radius:0 200px 200px 0;background-color:#fff;}
.circle-01,
.circle-02 {width:200px;height:200px;position:absolute;z-index:2;border-radius:300px;}
.circle-01 {top:0;left:100px;background-color:#000;}
.box-taiji {width:400px;height:400px;position:relative;margin:50px auto;border-radius:400px;background-color:#000;box-shadow:0 0 50px rgba(0,0,0,.8);}
.box-taiji:before,
.box-taiji:after {width:200px;height:400px;position:absolute;top:0;display:block;content:"";}
.box-taiji:before {left:0;border-radius:200px 0 0 200px;background-color:#000;}
.box-taiji:after {right:0;border-radius:0 200px 200px 0;background-color:#fff;}
.circle-01,
.circle-02 {width:200px;height:200px;position:absolute;z-index:2;border-radius:300px;}
.circle-01 {top:0;left:100px;background-color:#000;}
.circle-02 {bottom:0;right:100px;background-color:#fff;}
依次画两个宽高都为200px的圆，一黑一白。上下定位。
步骤四：
.box-taiji {width:400px;height:400px;position:relative;margin:50px auto;border-radius:400px;background-color:#000;box-shadow:0 0 50px rgba(0,0,0,.8);}
.box-taiji:before,
.box-taiji:after {width:200px;height:400px;position:absolute;top:0;display:block;content:"";}
.box-taiji:before {left:0;border-radius:200px 0 0 200px;background-color:#000;}
.box-taiji:after {right:0;border-radius:0 200px 200px 0;background-color:#fff;}
.circle-01,
.circle-02 {width:200px;height:200px;position:absolute;z-index:2;border-radius:300px;}
.circle-01 {top:0;left:100px;background-color:#000;}
.circle-02 {bottom:0;right:100px;background-color:#fff;}
.circle-01:after,
.circle-02:after {width:75px;height:75px;position:absolute;z-index:3;display:block;content:"";border-radius:75px;}
.circle-01:after {top:60px;left:55px;background-color:#fff;}
.circle-02:after {bottom:60px;right:55px;background-color:#000;}
组后两个黑白小圆，加上，布局效果搞定。
步骤五：
.box-taiji {width:400px;height:400px;position:relative;margin:50px auto;border-radius:400px;background-color:#000;box-shadow:0 0 50px rgba(0,0,0,.8);animation:rotation 2.5s linear infinite;-webkit-animation:rotation 2.5s linear infinite;-moz-animation:rotation 2.5s linear infinite;}
.box-taiji:before,
.box-taiji:after {width:200px;height:400px;position:absolute;top:0;display:block;content:"";}
.box-taiji:before {left:0;border-radius:200px 0 0 200px;background-color:#000;}
.box-taiji:after {right:0;border-radius:0 200px 200px 0;background-color:#fff;}
.circle-01,
.circle-02 {width:200px;height:200px;position:absolute;z-index:2;border-radius:300px;}
.circle-01 {top:0;left:100px;background-color:#000;}
.circle-02 {bottom:0;right:100px;background-color:#fff;}
.circle-01:after,
.circle-02:after {width:75px;height:75px;position:absolute;z-index:3;display:block;content:"";border-radius:75px;}
.circle-01:after {top:60px;left:55px;background-color:#fff;}
.circle-02:after {bottom:60px;right:55px;background-color:#000;}
@keyframes rotation {
0% {transform:rotate(0deg);}
100% {transform:rotate(360deg);}
}
@-webkit-keyframes rotation {
0% {-webkit-transform:rotate(0deg);}
100% {-webkit-transform:rotate(360deg);}
}
@-moz-keyframes rotation {
0% {-moz-transform:rotate(0deg);}
100% {-moz-transform:rotate(360deg);}
添加上动画效果，搞定、收工！！！
总结：
1、效果布局主要用了用了3个DIV，配合:before、:after利用css3中的圆角(border-radius)、阴影(box-shadow)完成。
2、动画效果CSS3中的@keyframes、animation