选择器
1 <!--这个样式用在p元素中-->2 p{3 color: maroon;4 } 把CSS放入HTML中
1 <!-- 放入style元素中，但不建议文件多的时候这样做 --> 2 <head> 3 <meta charset="utf-8"> 4 <title> HEAD FIRST CSS</title> 5 <style> 6 p{ 7 color: maroon; 8 } 9 </style>10 </head> 为一个或多个页面增加样式：
步骤：
- 取出html文件中的样式规则，把他们放在一个后缀名为.css的文件中。
- 从每个html文件创建一个到css文件的外部链接
- 做好测试
1 <!--这个样式在一个index.css文件中--> 2 p{ 3 color: maroon; 4 } 5 6 7 <!-- 在html文件中 --> 8 <head> 9 10 <meta charset = "utf-8">11 <title>head first Lounge</title>12 13 <!-- 链接到外部样式表的HTML -->14 <link rel="stylesheet" href="index.css">15 16 </head> 样式的继承 只能对体中的元素增加样式，所以元素不用作讨论
上图注释：
元素，就会影响到下面阴影部分的所有元素。
长江后浪推前浪，覆盖继承
然而，有些时候，不希望每个元素都继承样式。
但是，还好，浏览器总会使用更特定的规则
1 body{2 font-family:sans-serif;3 }4 5 /* 覆盖掉了从body继承的font-family属性 */6 em{7 font - family:serif;8 } 单独为某些段落设置样式
总是有些段落要特殊点的
不是吗？所以，有了类的存在，就像俱乐部
1 <!-- 在html文件中 -->2 <p class="specil">3 this is a specil people/class;4 </p>5 <p>6 this is 平常的 p;7 </p>
1 /*这个样式在一个index.css文件中*/2 p{3 font-family:sans-serif;4 }5 /*specil类的p ，覆盖掉了从p继承的样式，多个元素同属一个类时，为了一次设置多个元素，可以省略类前的元素名*/6 p.specil{7 color:green;8 } 谁是赢家？
什么？一个元素加入了多个俱乐部？
没事，选择器总是会选最特定（特定等级相同时选最后的）的样式
1 <!-- 在html文件中 -->2 <p class="specil big small">3 this is a specil people/class;4 </p>
1 /*选择所有段落*/ 2 p{ 3 4 color:black; 5 } 6 /*选择specil类所有成员，比上一个特定点*/ 7 .specil{ 8 color:green; 9 }10 /*这个规则只选specil类中段落，比前一个更特定*/11 p.specil{12 color:green;13 }14 p.specil{15 color:blue;16 } 结果：
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