CSS样式表-1 老师授课

 1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 2 <html xmlns="http://www.w3.org/1999/xhtml">
 3 <head>
 4 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 5 <title>无标题文档</title>
 6 
 7 <link href="Untitled-3.css" rel="stylesheet" type="text/css" />
 8 </head>
 9 
10 <body><br />
11 <a href="http://www.360.com/">360官网</a>
12 <br />
13 
14 <div style="background-color:#0F3">56123456</div>
15 <p>春来了。</p>
16 <p>春天花会开。</p>
17 <div class="aa" id="a1">1</div>
18 <div class="aa" id="a2"><p>2</p></div>
19 <div class="aa" id="a3">3</div>
20 <div class="aa" id="a4">4</div>
21 </body>
22 </html>

 1 @charset "utf-8";
 2 /* CSS Document */
 3 p/*针对所有p标签*/
 4 {
 5     font-size:36px;/*字体大小*/
 6     color:#F00;/*文字颜色*/
 7     background-color:#CF3;/*背景颜色*/}
 8 
 9 .aa
10 {
11     width:300px;
12     height:200px;
13     border:1px solid #F00;}
14 .aa p
15 {
16     font-size:36px;
17     color:#FF3;}
18 #a1
19 {
20     background-color:#0F3;}
21 #a2
22 {
23     background-color:#09C;}
24 #a3
25 {
26     background-color:#90C;}
27 #a4
28 {
29     background-color:#FF3;}
30 a
31 {
32     font-size:24px;}
33 a:link
34 {
35     text-decoration:none;
36     color:black;}
37 a:visited
38 {
39     text-decoration:none;
40     color:black;}
41 a:hover
42 {
43     text-decoration:underline;
44     color:red;}
45     a:active
46 {
47     text-decoration:underline;
48     color:orange;}