CSS的基本种类：标签选择器,类选择器,Id选择器,伪类选择器,伪元素选择器.
代码演示:
<!DOCTYPE html>
<html>
<head>
<title>网页设计复习</title>
<style>
h2{
/*color: red;*/
/*color:#ff0000;*/
/*color:#f00;*/
color:rgb(255,255,255);
background-color: grey;
width: 200px;
height: 60px;
text-align: center;
line-height: 60px;
box-shadow: 2px 2px 4px purple;
text-shadow: 2px 2px 4px purple;
}
h2:hover{
color:red;
background-color: blue;
position: relative;
left:2px;
bottom: 2px;
}
.weight{
font-weight: 900;
}
.big{
font-size: x-large;
}
#author{
border-bottom: 1px solid grey;
width: 200px;
text-align: center;
text-shadow: 2px 2px 4px purple;
}
p:hover:before{
content: ">>>"
}
</style>
</head>
<body>
<h2>网页设计复习</h2>
<h3 id="author">作者:马老师</h3>
<p class="weight">第1段文字</p>
<p class="big">第2段文字</p>
<p class="weight big">第3段文字</p>
</body>
</html>
