使用before和:after伪类制作css3圆形按钮两种CSS3伪类选择器详细介绍CSS3 :nth-child()伪类选择器实现奇偶行显示不同样式CSS3结构性伪类选择器九种写法CSS3 选择器 伪类选择器介绍利用CSS3的checked伪类实现OL的隐藏显示的方法CSS3 伪类选择器 nth-child()说明详解css3中的伪类before和after常见用法

* {
padding: 0;
margin: 0;
}
/* 清除浮动 */
.clearfix:after {
content: "";
display: table;
clear: both;
}
html, body {
height: 100%;
}
body {
font-family: "Microsoft YaHei";
background: #E1E1E1;
font-weight: 300;
font-size: 15px;
color: #333;
overflow: hidden;
}
a {
text-decoration: none;
}
/*按钮 阴影无扩展 */
.bt {
margin: 100px auto;
display: block;
width: 350px;
opacity:0;
border-bottom: 1px solid #C5C5C5;
border-top: 1px solid #C5C5C5;
box-shadow: 0 1px 0 #F6F6F6, 0 1px 0 #F6F6F6 inset;
transition: all 0.5s ease-in;
}

.button:before, .button2:before {
content: "";
width: 130px;
height: 130px;
display: block;
z-index: -1;
position: relative;
background: #ddd;
left: -15px;
top: -15px;
border-radius: 65px;
box-shadow: inset 2px 2px 4px rgba(0,0,0,0.4);
}
.button:after, .button2:after {
content: "注册";
color: #09F;
font-size: 20px;
width: 100%;
height: 100%;
line-height: 100px;
text-align: center;
position: absolute;
top: 0;
display: block;
}
.button2:after {
content: "登入";
word-spacing: 25px;
color: #A0D989;
}
.button, .button2 {
float: left;
margin: 50px auto;
cursor: pointer;
height: 100px;
width: 100px;
display: block;
position: relative;
color: black;
text-align: center;
line-height: 100px;
border-radius: 50px;
box-shadow: 2px 2px 4px rgba(0,0,0,0.4);
background: #FFF;
transition: all 0.5s ease-in;
}
.button {
float: left;
}
.button2 {
float: right;
}