a标签 必须按顺序写
link 链接未访问的时候的样式
visited 链接访问后的样式
hover 鼠标放上去的样式
active 链接在访问时的样式
after
before
nth-of-type(2n) ?选择属于其父级下面第n个元素
隔行换色：
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 ????<meta charset="UTF-8"> 5 ????<title>Title</title> 6 ????<style> 7 ????????p:nth-of-type(2n){ 8 ????????????background: red; 9 ????????}10 ????????p:nth-of-type(2n-1){11 ????????????background-color: gold;12 ????????}13 ????</style>14 </head>15 <body>16 ????<p>1</p>17 ????<p>2</p>18 ????<p>3</p>19 ????<p>4</p>20 ????<p>5</p>21 ????<p>6</p>22 </body>23 </html> 1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 ????<meta charset="UTF-8"> 5 ????<title>Title</title> 6 ????<style> 7 ????????div{ 8 ????????????width: 980px; 9 ????????????margin: 0 auto;10 ????????????overflow: auto;11 ????????}12 ????????span{13 ????????????float: left;14 ????????????width: 300px;15 ????????????height: 300px;16 ????????????background-color: red;17 ????????????margin:10px ;18 ????????}19 ????????span:nth-of-type(3n-1){20 ????????????margin-left: 10px;21 ????????????margin-right: 10px;22 ????????}23 ????</style>24 </head>25 <body>26 <div>27 ????<span>1</span>28 ????<span>2</span>29 ????<span>3</span>30 ????<span>4</span>31 ????<span>5</span>32 ????<span>6</span>33 ????<span>7</span>34 ????<span>8</span>35 ????<span>9</span>36 ????<span>10</span>37 ????<span>11</span>38 ????<span>12</span>39 </div>40 </body>41 </html>css 伪类
原文地址：https://www.cnblogs.com/koushuige/p/8323668.html