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<html>
  <head>
    <style type="text/css">
    #sidebar p {
        font-family: Verdana;
        font-size: .9em; }

        #sidebar .intro {
            font-family: Georgia;
            font-size: 1.25em;
            color:red;
            }

    </style>

  </head>
  <body>
    <div id=”sidebar”&gt;
       <p class=”intro”&gt;
           As you can see, the more CSS styles you create, the greater the potential for formatting
          snafus. For example, you may create a class style specifying a particular
         font and font size, but when you apply the style to a paragraph, nothing happens!
          This kind of problem is usually related to the cascade. Even though you may think
         that directly applying a class to a tag should apply the class’s formatting properties,
          it may not if there’s a style with greater specificity.

        You have a couple of options for dealing with this kind of problem. First, you can
        use !important (as described in the box above) to make sure a property always
        applies. The !important approach is a bit heavy handed, though, since it’s hard to
        predict that you’ll never, ever, want to overrule an !important property someday.
        Read on for two other cascade-tweaking solutions.
    </p>    
</div>

  </body>
</html>

#sidebar p样式的特异性为 101（ID 为 100，标签选择器为 1），而.intro 样式的特异性为10（类选择器为 10 分）。由于 101 大于 10，所以 #sidebar p 优先。将 .intro 更改为 #sidebar .intro 会将其特异性更改为 110。

即使我改变了这一点，我的结果也不会到来

谁能给我解释一下。

输出：应该是红色，font-size-1.25em 和 font-family -Georgia

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1 回答 1

1
于 2012-08-05T16:38:14.507 回答