1 <!doctype html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <meta name="Generator" content="EditPlus®"> 6 <meta name="Author" content=""> 7 <meta name="Keywords" content=""> 8 <meta name="Description" content=""> 9 <title>Document</title> 10 <style type="text/css"> 11 div{ 12 width:300px; 13 height:30px; 14 background:yellow; 15 } 16 #heizi{ 17 width:200px; 18 height:20px; 19 background:blue; 20 } 21 .objk{ 22 width:100px; 23 height:10px; 24 background:green; 25 } 26 </style> 27 <!-- 28 class相当于名字， 而id相当于是身份证(唯一性);所有当多个同类标签需要用到同一样式时需要用class(可以有多个名称); 29 --> 30 </head> 31 <body> 32 <div id="heizi">小猪佩奇</div> 33 <div class="ojbk ooo pppp mmm">可爱龙猫</div> 34 <div class="objk" style="500px;height:50px;background:pink;">泡泡小鱼</div> 35 </body> 36 </html>