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CSS3选择器学习笔记

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May 26, 2016 pm 03:25 PM

CSS选择器总结：

一．基本选择器

1.通配选择器：[ * ] 选择文档中所以HTML元素。

<span style="color: #000000;"> *{margin: 0;padding: 0;} /*选择页面中的所有元素并设置margin和padding值为0*/
 .mumu *{background:#000;} /*选择类名为mumu的元素下面的所有元素设置背景为黑色*/</span>

2.元素选择器：[ E ] 选择指定类型的HTML元素。

p{color:red;} /*选择p元素*/

3.ID选择器： [ #id ] 选择指定ID属性值为“id”的任意类型元素。

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
#div1</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">width</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">100px</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#000</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;">    <span style="color: #800000;">div </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="div1"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span>

4.类选择器: [ .class ] 选择指定class属性值为“class”的任意类型的任意多个元素.

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
.mumu</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">width</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">100px</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#000</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;">    <span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="mumu"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span>

5.群组选择器: [ selector1,selectorN ] 将每一个选择器匹配的元素集合并.

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
.section-1,.section-2,.section-3</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#000</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #800000;"> /*给三个div定义公用的样式 */
</span><span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;">    <span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="section-1"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;">    <span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="section-2"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;">    <span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="section-3"</span><span style="color: #0000ff;">></span>3<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span>

二．层次选择器

1.后代选择器：[ E F ] 选择匹配的F元素，且匹配的F元素被包含在匹配的E元素内。

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
.div1 div</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#000</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #800000;"> /*选择div1里面的所有div*/
</span><span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div1"</span><span style="color: #0000ff;">></span>
        <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div2"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
        <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div3"</span><span style="color: #0000ff;">></span>3<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span>

2.子选择器：[ E>F ] 选择匹配的F元素，且匹配的F元素是所匹配的E元素的直系子元素

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
.div1>div</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#000</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #800000;"> /*选择div1里面的div1,div2和div3,不会选到div*/
</span><span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div1"</span><span style="color: #0000ff;">></span>
        <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div2"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
        <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div3"</span><span style="color: #0000ff;">></span>
            <span style="color: #0000ff;"><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>4<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
        <span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span></span>

3.相邻兄弟元素选择器：[ E+F ] 选择匹配的F元素，且匹配的F元素紧位于匹配的E元素的后面

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
.div2+p</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#000</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #800000;"> /*选择div2后面的第一个p元素*/
</span><span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div1"</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div2"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span></span>

4.通用选择器： [ E~F ] 选择匹配的F元素，且位于匹配的E元素后的所有匹配的F元素（E和F是同辈元素，具有相同的父元素）

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
.div2~p</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#000</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #800000;"> /*选择div2后面所有的p元素*/
</span><span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div1"</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="div2"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span></span>

三.属性选择器

1. E[attr] 只使用属性名，但没有确定任何属性值

<span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    p[id]</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">red</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #800000;">
    p[mumu]</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">blue</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span> <span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">将会选择具有[attr]属性的p标签</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="zM"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="xm"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span>

2.E[attr=value] 指定属性名，并指定了该属性的属性值

<span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    p[mumu=zM]</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">blue</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span> <span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">将会选择具有mumu属性且值为zM的p标签</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="zM"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="xm"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span>

3.E[attr~=value] 指定属性名，并且具有属性值，此属性值是一个词列表，并且以空格隔开，其中词列表中只要包含了一个value词就会被选中

<span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    p[mumu~=big]</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">blue</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择具有mumu属性且其中一个属性值为big的p标签</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="zM big"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="xm"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span>

4.E[attr^=value]指定了属性名，并且有属性值，属性值是以value开头的

<span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    p[mumu^=x]</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">blue</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择mumu属性以x开头的 p标签</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="zM big"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="xm"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="rm"</span><span style="color: #0000ff;">></span>3<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span>

5.E[attr$=value]指定了属性名，并且有属性值，而且属性值是以value结束的

<span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    p[mumu$=m]</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#CC0</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择mumu属性以m结尾的 p标签</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="zM big"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="xm"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="rm"</span><span style="color: #0000ff;">></span>3<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span>

6.E[attr*=value]指定了属性名，并且有属性值，而且属值中包含了value

<span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    p[mumu*=g]</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#CC0</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择mumu属性值里包含g的 p标签</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="zM big"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="xm"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="gm"</span><span style="color: #0000ff;">></span>3<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span>

7.E[attr|="value"]指定了属性名，并且属性值是value或者以“value-”开头的值（比如说b-cn）

<span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    p[mumu|=b]</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#CC0</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择mumu属性值里以b或者b-开头的 p标签</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="b-zM big"</span><span style="color: #0000ff;">></span>1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="b-xm"</span><span style="color: #0000ff;">></span>2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="gm"</span><span style="color: #0000ff;">></span>3<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p </span><span style="color: #ff0000;">mumu</span><span style="color: #0000ff;">="b"</span><span style="color: #0000ff;">></span>4<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span></span></span></span></span></span></span>

四．伪类选择器

1.动态伪类选择器

<span style="color: #0000ff;"><span style="color: #800000;">style </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/css"</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
        E:link   </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择匹配的E元素，而且匹配元素被定义了超链接并未被访问过。常用于链接描点上</span><span style="background-color: #f5f5f5; color: #008000;">*/</span><span style="background-color: #f5f5f5; color: #800000;">
        E:visited   </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择匹配的E元素，而且匹配元素被定义了超链接并已被访问过。常用于链接描点上</span><span style="background-color: #f5f5f5; color: #008000;">*/</span><span style="background-color: #f5f5f5; color: #800000;">
        E:active  </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择匹配的E元素，且匹配元素被激活。常用于链接描点和按钮上</span><span style="background-color: #f5f5f5; color: #008000;">*/</span><span style="background-color: #f5f5f5; color: #800000;">
        E:hover  </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择匹配的E元素，且用户鼠标停留在元素E上。IE6及以下浏览器仅支持a:hover</span><span style="background-color: #f5f5f5; color: #008000;">*/</span><span style="background-color: #f5f5f5; color: #800000;">
        E:focus  </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">选择匹配的E元素，而且匹配元素获取焦点</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span></span>

2.目标伪类选择器

[ E:target ] 功能：选择匹配E的所有元素，且匹配元素被相关URL指向

<span style="color: #0000ff;"><span style="color: #ff00ff;">DOCTYPE html</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">html </span><span style="color: #ff0000;">lang</span><span style="color: #0000ff;">="en"</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">meta </span><span style="color: #ff0000;">charset</span><span style="color: #0000ff;">="UTF-8"</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>Document<span style="color: #0000ff;"></span><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    div</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">width</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">300px</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;">height</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">200px</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#000</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;"> font</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">50px/200px "微软雅黑"</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;"> color</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">#fff</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;"> text-align</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">center</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;"> display</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">none</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #800000;">
    div:target</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;"> display</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">block</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">a </span><span style="color: #ff0000;">href</span><span style="color: #0000ff;">="#div1"</span><span style="color: #0000ff;">></span>div1<span style="color: #0000ff;"></span><span style="color: #800000;">a</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">a </span><span style="color: #ff0000;">href</span><span style="color: #0000ff;">="#div2"</span><span style="color: #0000ff;">></span>div2<span style="color: #0000ff;"></span><span style="color: #800000;">a</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">a </span><span style="color: #ff0000;">href</span><span style="color: #0000ff;">="#div3"</span><span style="color: #0000ff;">></span>div3<span style="color: #0000ff;"></span><span style="color: #800000;">a</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="div1"</span><span style="color: #0000ff;">></span>div1<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="div2"</span><span style="color: #0000ff;">></span>div2<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="div3"</span><span style="color: #0000ff;">></span>div3<span style="color: #0000ff;"></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">html</span><span style="color: #0000ff;">></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

3.否定伪类选择器

[ E:not(s) ] 表示匹配所有除元素F外的E元素

<span style="color: #0000ff;"><span style="color: #ff00ff;">DOCTYPE html</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">html </span><span style="color: #ff0000;">lang</span><span style="color: #0000ff;">="en"</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">meta </span><span style="color: #ff0000;">charset</span><span style="color: #0000ff;">="UTF-8"</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>Document<span style="color: #0000ff;"></span><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    h1:not(.h2)</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;"> background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">Red</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>h1<span style="color: #0000ff;"></span><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">h1 </span><span style="color: #ff0000;">class</span><span style="color: #0000ff;">="h2"</span><span style="color: #0000ff;">></span>h1<span style="color: #0000ff;"></span><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>h1<span style="color: #0000ff;"></span><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">html</span><span style="color: #0000ff;">></span></span></span></span></span></span></span></span></span></span></span>

4.状态伪类选择器

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    E:disabled; </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">表示不可点击的表单控件</span><span style="background-color: #f5f5f5; color: #008000;">*/</span><span style="background-color: #f5f5f5; color: #800000;">
    E:enabled; </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">表示可点击的表单控件</span><span style="background-color: #f5f5f5; color: #008000;">*/</span><span style="background-color: #f5f5f5; color: #800000;">
    E:checked; </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">表示已选中的checkbox或radio</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span></span>

5.结构伪类选择器

E:nth-child(n) 表示E父元素中的第n个字节点（从前往后数），注意：CSS3中计数是从1开始,n可运算

<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    E:nth-child(odd)</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">red</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">匹配奇数行或者nth-child(2n+1)</span><span style="background-color: #f5f5f5; color: #008000;">*/</span><span style="background-color: #f5f5f5; color: #800000;">
    E:nth-child(even)</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">red</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">匹配偶数行或者nth-child(2n)</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span></span>

<span style="color: #0000ff;"><span style="color: #ff00ff;">DOCTYPE html</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">html </span><span style="color: #ff0000;">lang</span><span style="color: #0000ff;">="en"</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">meta </span><span style="color: #ff0000;">charset</span><span style="color: #0000ff;">="UTF-8"</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>Document<span style="color: #0000ff;"></span><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    body *:nth-child(2)</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">red</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">
    p:nth-child(2){background:red;}会没有变化
    因为：p:nth-child(2) 找p标签父级下的第二个子元素，并且这个元素还的是p标签
    </span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>h1<span style="color: #0000ff;"></span><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>h2<span style="color: #0000ff;"></span><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p3<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>h3<span style="color: #0000ff;"></span><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p4<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p5<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">html</span><span style="color: #0000ff;">></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

E:nth-last-child(n) 表示E父元素中的第n个字节点，从后向前计算

E:nth-of-type(n) 表示E父元素中的第n个字节点，且类型为E，从前往后计算

E:nth-last-of-type(n) 表示E父元素中的第n个字节点，且类型为E,从后向前计算

<span style="color: #0000ff;"><span style="color: #ff00ff;">DOCTYPE html</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">html </span><span style="color: #ff0000;">lang</span><span style="color: #0000ff;">="en"</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">meta </span><span style="color: #ff0000;">charset</span><span style="color: #0000ff;">="UTF-8"</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>Document<span style="color: #0000ff;"></span><span style="color: #800000;">title</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">style</span><span style="color: #0000ff;">></span><span style="background-color: #f5f5f5; color: #800000;">
    p:nth-of-type(2)</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">red</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">找p标签父级下的第二个p元素</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
<span style="color: #0000ff;"></span><span style="color: #800000;">style</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"></span><span style="color: #800000;">head</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">body</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p1<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>h1<span style="color: #0000ff;"></span><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>p2<span style="color: #0000ff;"></span><span style="color: #800000;">p</span><span style="color: #0000ff;">></span>
    <span style="color: #0000ff;"><span style="color: #800000;">h1</span><span style="color: #0000ff;">></span>h2<span style="color: #0000ff;"></span><sp></sp></span></span></span></span></span></span></span></span></span></span></span>

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