Pseudo-class hover is invalid, about the priority of CSS_html/css

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Pseudo-class hover is invalid, about the priority of CSS_html/css_WEB-ITnose

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Jun 24, 2016 am 11:41 AM

<!DOCTYPE html><html><head lang="en">    <meta charset="UTF-8">    <title></title>    <style>        a:hover{            color: #B61D1D;        }        .tag_a{            color: #333;        }        .tag_ul a{            color: #333;        }    </style></head><body>    //hover失效    <ul class="tag_ul">        <li><a>用ul标签选中</a></li>    </ul>        //hover失效有效    <ul>        <li><a class="tag_a">用a标签选中</a></li>    </ul></body></html>

有没有大神帮我解释一下关于class的优先级！

回复讨论(解决方案)

用a标签选中

加上href

既然楼主自己都试出加class后有效，，，那就加个class不就好了。。。

顺序为
a
a:visited
a:hover
a:active

权重(摘自《CSS实战手册》)

引入

示例

                                           a {background-color: blue ;}
.nav li a {background-color: silver;}

The background color of ?

Weight calculation

Principle
Determine the weight of the style based on the value assigned to the style selector (label selector, class selector, ID selector)
> Ways
A tag selector 1 point
A class selector 10 points
An ID selector 100 points
A built-in style 1000 points
Example
.navBox a
10 1 = 11 points
.navBox .nav a
10 10 1 = 21 points
.nav a
10 1 = 11 points
.nav li a
10 1 1 = 12 points

Notes
1) Inherited attributes do not have any weight value
2) When the weight values are the same, the last style wins
3) List all external style sheets first, Then incorporate the internal style.

Ignore the weight value

Description
CSS provides a way to completely ignore the weight value.
When you must and must ensure a specific When the properties of the property are not overridden by another more specific style,
       You can use this technique
     Just insert !important after the property that needs to be protected to avoid being overwritten by a property with a greater weight.
     Example
.navBox .nav a {background-color: red;}
a {background-color: black!important;}

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