开着途达游世界 發表於 2019-7-3 14:42:00

python 学习_第五模块 CSS(二)

<h1 style="text-align: center"><strong><span style="font-family: 隶书; font-size: 18pt">python 学习_第五模块 CSS(二)</span></strong></h1>
<p>&nbsp;</p>
<h2><span style="font-family: 隶书">一 行内元素分类</span></h2>
<h3><strong><span style="font-family: 隶书">1&nbsp;</span></strong><span style="font-family: 隶书">块级元素</span></h3>
<p><span style="font-family: 隶书; font-size: 16px">    (1)独自占一行</span><br><span style="font-family: 隶书; font-size: 16px">    (2)可以设置宽高,如果不设置宽,默认是父标签的100%宽</span></p>
<p><span style="font-family: 隶书; font-size: 16px">      display:block;</span></p>
<h3><strong>2 行内元素</strong></h3>
<p><span style="font-family: 隶书; font-size: 16px">    (1)行内元素在一行内显示</span><br><span style="font-family: 隶书; font-size: 16px">    (2)不能设置宽高</span></p>
<p><span style="font-family: 隶书; font-size: 16px">      display:inline;</span></p>
<h3><strong>3 行内块元素</strong></h3>
<p><span style="font-family: 隶书; font-size: 16px">    (1)在一行内显示</span><br><span style="font-family: 隶书; font-size: 16px">    (2)可以设置宽高</span></p>
<p><span style="font-family: 隶书; font-size: 16px">      display:inline-block;</span></p>
<p><span style="font-family: 隶书; font-size: 18px">&nbsp;</span></p>
<div class="cnblogs_code">
<pre><span style="color: rgba(128, 0, 0, 1)"> &lt;!-- 1 块级元素 --&gt;
&lt;div&gt;&lt;/div&gt;
&lt;p&gt;&lt;/p&gt;
&lt;h1&gt;&lt;/h1&gt;
&lt;ul&gt;
    &lt;li&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;ol&gt;
    &lt;li&gt;&lt;/li&gt;
&lt;/ol&gt;
&lt;dl&gt;
    &lt;dt&gt;&lt;/dt&gt;
    &lt;dd&gt;&lt;/dd&gt;
&lt;/dl&gt;
      
&lt;!-- 2 行内元素 --&gt;
&lt;a href=""&gt;&lt;/a&gt;
&lt;span&gt;&lt;/span&gt;
&lt;strong&gt;&lt;/strong&gt;
&lt;em&gt;&lt;/em&gt;

&lt;!-- 3 行内块元素 --&gt;
&lt;input type="text" name=""&gt;
&lt;img src="images/index02.jpeg"&gt;</span></pre>
</div>
<p><strong><span style="background-color: rgba(136, 136, 136, 1)">    行内元素&nbsp; 设置&nbsp;display: inline-block;&nbsp; &nbsp;就变成行内块元素&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;</span></strong></p>
<p>&nbsp;</p>
<h3><span style="font-family: 隶书; font-size: 18px"><strong>4 元素分类示例</strong></span></h3>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>元素分类<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      div</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      p</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      a,span</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            font-size</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 30px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> purple</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 300px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 300px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      input</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 300px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 50px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      img</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> 1 块级元素
            (1)独自占一行
            (2)可以设置宽高,如果不设置宽,默认是父标签的100%宽
      2 行内元素
            (1)行内元素在一行内显示
            (2)不能设置宽高
      3 行内块元素
            (1)在一行内显示
            (2)可以设置宽高
   </span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>
   <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> 1 块级元素 </span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>MJJ<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>我是一个段落<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">h1</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>mjj<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">h1</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
         <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>小米商城<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
         <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>小米商城<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   
   <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> 2 行内元素 </span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">href</span><span style="color: rgba(0, 0, 255, 1)">="#"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>百度一下<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>小猿圈<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">strong</span><span style="color: rgba(0, 0, 255, 1)">&gt;&lt;/</span><span style="color: rgba(128, 0, 0, 1)">strong</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">em</span><span style="color: rgba(0, 0, 255, 1)">&gt;&lt;/</span><span style="color: rgba(128, 0, 0, 1)">em</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   
      <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> 3 行内块元素 </span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">input </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text"</span><span style="color: rgba(255, 0, 0, 1)"> name</span><span style="color: rgba(0, 0, 255, 1)">=""</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">input </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="password"</span><span style="color: rgba(255, 0, 0, 1)"> name</span><span style="color: rgba(0, 0, 255, 1)">=""</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">img </span><span style="color: rgba(255, 0, 0, 1)">src</span><span style="color: rgba(0, 0, 255, 1)">="images/index02.jpeg"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
   <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">img </span><span style="color: rgba(255, 0, 0, 1)">src</span><span style="color: rgba(0, 0, 255, 1)">="images/index02.jpeg"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<h2>二 display 属性</h2>
<p>&nbsp;</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">meta </span><span style="color: rgba(255, 0, 0, 1)">charset</span><span style="color: rgba(0, 0, 255, 1)">="utf-8"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>display属性<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      div</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)">200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">元素隐藏</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            display</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>            
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      a,span</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 40px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">display: inline-block设置为行内块元素 </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            display</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> inline-block</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">text-align: center; 水平居中
            line-height=height 控制文本垂直居中</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            text-align</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> center</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            line-height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 40px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>

            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">关闭超链接的下划线</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            text-decoration</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>

    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>我是块元素<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>我是行内元素<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">href</span><span style="color: rgba(0, 0, 255, 1)">="#"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>行内块元素小圆圈<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;<img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190703145651853-1589305955.png" alt=""></p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">meta </span><span style="color: rgba(255, 0, 0, 1)">charset</span><span style="color: rgba(0, 0, 255, 1)">="utf-8"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>小米顶部栏案例<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      a </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            text-decoration</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .top_bar </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100%
            height:40px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> #333</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .top_bar a</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> #b0b0b0</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">display: inline-block设置为行内块元素 </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            display</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> inline-block</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            line-height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 40px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">background-color: red;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .top_bar span</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> #424242</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .top_bar a:hover</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> #fff</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="top_bar"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">href</span><span style="color: rgba(0, 0, 255, 1)">="#"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>小米商场<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>|<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">href</span><span style="color: rgba(0, 0, 255, 1)">="#"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>MIUI<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>|<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">href</span><span style="color: rgba(0, 0, 255, 1)">="#"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>IoT<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>|<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">href</span><span style="color: rgba(0, 0, 255, 1)">="#"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>云服务<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;<img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190703145817798-630887048.png" alt=""></p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<h2>三 盒模型的属性</h2>
<p>&nbsp;</p>
<p><strong><span style="font-family: 隶书; font-size: 18px">width:内容的宽高</span></strong><br><strong><span style="font-family: 隶书; font-size: 18px">height:内容的高</span></strong><br><strong><span style="font-family: 隶书; font-size: 18px">padding:内边距</span></strong><br><strong><span style="font-family: 隶书; font-size: 18px">border:边框</span></strong><br><strong><span style="font-family: 隶书; font-size: 18px">margin:外边距</span></strong></p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>盒子模型的属性<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      div</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            padding-top</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 50px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 3px solid green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>augustyang<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;<img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190703155218771-1070509134.png" alt="" width="1067" height="351"></p>
<p>&nbsp;</p>
<h3><strong><span style="font-family: 隶书; font-size: 18px">1 padding</span></strong></h3>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">meta </span><span style="color: rgba(255, 0, 0, 1)">charset</span><span style="color: rgba(0, 0, 255, 1)">="utf-8"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>padding的讲解<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      div</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 180px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 180px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">padding-top: 20px;
            padding-rigth: 20px;
            padding-bottom: 20px;
            padding-right: 50px;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>

            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)"> 上右下 左</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">padding: 20px;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)"> 上下   左右</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">padding: 20px 40px;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)"> 上   右下左</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">padding: 20px 30px 40px;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)"> 上右下 左</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            padding</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 10px 20px 30px 40px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>

      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>

    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>augustyang<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<h3><strong><span style="font-family: 隶书; font-size: 14pt">2 border</span></strong></h3>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>边框border<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">border: 1px solid red;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">按照三要素来编写border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">border-width: 4px 10px;
            border-style: solid dotted double dashed;
            border-color: green red purple yellow;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>

            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">按照方向来编写border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">
            border-top-width: 4px;
            border-top-color: red;
            border-top-style: solid;

            border-bottom-width: 4px;
            border-bottom-color: red;
            border-bottom-style: solid;
            </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      input</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">清除默认样式</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">border: none;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">或者</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 0</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">清除外线</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            outline</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">outline: 0;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .username</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 180px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 40px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            font-size</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 20px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            padding-left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 10px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid #666</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .username:hover</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid orange</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>

    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> 三要素: 粗细(width)样式 (style) 颜色 (color)</span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="border"</span><span style="color: rgba(0, 0, 255, 1)">&gt;&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">input </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text"</span><span style="color: rgba(255, 0, 0, 1)"> name</span><span style="color: rgba(0, 0, 255, 1)">=""</span><span style="color: rgba(255, 0, 0, 1)"> class</span><span style="color: rgba(0, 0, 255, 1)">="username"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<h3><strong><span style="font-family: 隶书; font-size: 18px">3 margin</span></strong></h3>
<p>&nbsp;</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>外边距margin<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      span</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)">red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .xiongda </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            margin-right</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)">20px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .xionger</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            margin-left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 30px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      div</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">margin 垂直方向上 会出现外边距合并   外边距塌陷</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .box1</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            margin-bottom</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 30px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .box2</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            margin-top</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 70px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>

    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> 外边距: 一个盒子到另一个盒子的距离 </span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">span </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="xiongda"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>熊大<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;&lt;</span><span style="color: rgba(128, 0, 0, 1)">span </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="xionger"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>熊二<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="box1"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>box1<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="box2"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>box2<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p><strong><span style="font-family: 隶书; font-size: 18px"><img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190703170048896-1524401474.png" alt=""></span></strong></p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<h3><strong><span style="font-family: 隶书; font-size: 18px">4 清除HTML标签元素的默认样式</span></strong></h3>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">meta </span><span style="color: rgba(255, 0, 0, 1)">charset</span><span style="color: rgba(0, 0, 255, 1)">="utf-8"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>清除HTML标签元素的默认样式<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      

      body,p,ul,ol,dl,dt</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            margin</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 0</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            padding</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 0</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      ul,ol</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            list-style</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      input</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            outline</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      a</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            text-decoration</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>


    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>我是个段落<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>我是个段落<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>augustyang<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">input </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text"</span><span style="color: rgba(255, 0, 0, 1)"> name</span><span style="color: rgba(0, 0, 255, 1)">=""</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p><img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190703171215467-2108633559.png" alt=""></p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">meta </span><span style="color: rgba(255, 0, 0, 1)">charset</span><span style="color: rgba(0, 0, 255, 1)">="utf-8"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>盒子居中<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">link </span><span style="color: rgba(255, 0, 0, 1)">rel</span><span style="color: rgba(0, 0, 255, 1)">="stylesheet"</span><span style="color: rgba(255, 0, 0, 1)"> type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(255, 0, 0, 1)"> href</span><span style="color: rgba(0, 0, 255, 1)">="css/reset.css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .top_bar</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100%</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 40px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> #333</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .container</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100%</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">margin-left:auto;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">margin-right: auto;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            margin</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 0 auto</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>


    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="top_bar"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="container"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
            小米商城
      </span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p><img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190703180120554-19217847.png" alt=""></p>
<p>&nbsp;</p>
<h2><span style="font-family: 隶书; font-size: 14pt"><strong>四 浮动与清除浮动</strong></span></h2>
<p>&nbsp;</p>
<h3><strong><span style="font-family: 隶书; font-size: 16px">1 文字环绕</span></strong></h3>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">meta </span><span style="color: rgba(255, 0, 0, 1)">charset</span><span style="color: rgba(0, 0, 255, 1)">="utf-8"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>文字环绕<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">link </span><span style="color: rgba(255, 0, 0, 1)">rel</span><span style="color: rgba(0, 0, 255, 1)">="stylesheet"</span><span style="color: rgba(255, 0, 0, 1)"> type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(255, 0, 0, 1)"> href</span><span style="color: rgba(0, 0, 255, 1)">="css/reset.css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .box img</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .box p</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100%</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="box"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">img </span><span style="color: rgba(255, 0, 0, 1)">src</span><span style="color: rgba(0, 0, 255, 1)">="images/index02.jpeg"</span><span style="color: rgba(255, 0, 0, 1)"> width</span><span style="color: rgba(0, 0, 255, 1)">="100"</span><span style="color: rgba(255, 0, 0, 1)"> height</span><span style="color: rgba(0, 0, 255, 1)">="100"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>有一对男女正在吃晚餐那个女生一直问那个男生 :你爱不爱我 ?男生看了女生一眼又继续吃晚餐女生很生气又再问了一次: 你爱不爱我?男生终于说 :爱女生又问 :那你要怎么证明?忽然男生从口袋里拿了三十元出来 ,且问女生 :你有没有十元?女生拿了十元给了男生..男生就把四十元放在桌上过了一会儿 .. ...女生很生气的问男生 :你到底要不要证明你爱我啊男生说:我己经证明了啊!!! 四十摆在眼前!有一对男女正在吃晚餐那个女生一直问那个男生 :你爱不爱我 ?男生看了女生一眼又继续吃晚餐女生很生气又再问了一次: 你爱不爱我?男生终于说 :爱女生又问 :那你要怎么证明?忽然男生从口袋里拿了三十元出来 ,且问女生 :你有没有十元?有一对男女正在吃晚餐那个女生一直问那个男生 :你爱不爱我 ?男生看了女生一眼又继续吃晚餐女生很生气又再问了一次: 你爱不爱我?<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p><img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190704174459492-1415392124.png" alt=""></p>
<p>&nbsp;</p>
<h3><span style="font-family: 隶书; font-size: 16px"><strong>2 浮动现象</strong></span></h3>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>浮动现象<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      div</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">width: 200px;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> #fff</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
            div.left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
                background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
                float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
            div.right</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
                background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
                float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
            div.center</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
                background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> orange</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
                float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> 浮动的现象
      0 文字环绕
      1 脱离标准的文档流
      2 浮动元素互相贴靠
      3 浮动元素有收缩现象

   </span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="left"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>左盒子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="right"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>中盒子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="center"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>右盒子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;<img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190704174546267-136065180.png" alt=""></p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<h3><strong><span style="font-family: 隶书; font-size: 16px">3 浮动的破坏性</span></strong></h3>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">meta </span><span style="color: rgba(255, 0, 0, 1)">charset</span><span style="color: rgba(0, 0, 255, 1)">="utf-8"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>浮动元素的破坏性<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .top_bar</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .child1</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .child2</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> orange</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> right</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .header</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100%</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> purple</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="top_bar"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="child1"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>儿子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="child2"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>二儿子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="header"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;<img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190704174749284-1489495802.png" alt=""></p>
<h3><strong><span style="font-family: 隶书; font-size: 16px">4 清除浮动的方式</span></strong></h3>
<div class="cnblogs_code"><img id="code_img_closed_2be56c9e-0aee-4861-b0d2-9d091f279683" class="code_img_closed" src="https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif" alt=""><img id="code_img_opened_2be56c9e-0aee-4861-b0d2-9d091f279683" class="code_img_opened" style="display: none" src="https://images.cnblogs.com/OutliningIndicators/ExpandedBlockStart.gif" alt="">
<div id="cnblogs_code_open_2be56c9e-0aee-4861-b0d2-9d091f279683" class="cnblogs_code_hide">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>清除浮动的方式<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      p a </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">text-decoration</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> none</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .top_bar</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .child1</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .child2</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> orange</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> right</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .header </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100%</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)">purple</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>

      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .clear</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            clear</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> both</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
   
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">给浮动子元素的父盒子,也就是不浮动元素,添加一个clearfix的类,然后设置</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">伪元素清除法</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .clearfix::after</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            content</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)">''</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            display</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> block</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            clear</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> both</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> 1.给父元素设置固定高度
            缺点: 使用不灵活 后期不易维护
            应用:网页中盒子固定高度区域,比如固定的导航栏
      2.内墙法(了解)
            规则: 在最后一个浮动元素的后面加一个空的块级元素,并且设置该属性clear: both;
            缺点: 结构冗余
      重要:
      3.伪元素(选择器)清除法
      4.overflow:hidden;
   </span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>


    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="top_bar clearfix"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="child1"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>儿子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="child2"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>二儿子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 128, 0, 1)">&lt;!--</span><span style="color: rgba(0, 128, 0, 1)"> &lt;div class="clear"&gt;&lt;/div&gt; </span><span style="color: rgba(0, 128, 0, 1)">--&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="header"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;&lt;</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">href</span><span style="color: rgba(0, 0, 255, 1)">="#"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>百度一下<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">&gt;&lt;/</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<span class="cnblogs_code_collapse">清除浮动的方式</span></div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p><img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190704174900441-1216022658.png" alt=""></p>
<h3><strong><span style="font-family: 隶书; font-size: 16px">5 overflow</span></strong></h3>
<div class="cnblogs_code"><img id="code_img_closed_6763312f-a812-4672-82f7-da6cf7adc9a0" class="code_img_closed" src="https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif" alt=""><img id="code_img_opened_6763312f-a812-4672-82f7-da6cf7adc9a0" class="code_img_opened" style="display: none" src="https://images.cnblogs.com/OutliningIndicators/ExpandedBlockStart.gif" alt="">
<div id="cnblogs_code_open_6763312f-a812-4672-82f7-da6cf7adc9a0" class="cnblogs_code_hide">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>overflow<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      body </span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            overflow</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> scroll</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .test1</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 300px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            overflow</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> scroll</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .test2</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 300px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            overflow</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> hidden</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .test3</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 300px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            overflow</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> auto</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">

      .test4</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 300px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            overflow</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> visible</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>



<span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">
overflow: scroll: 内容会被修剪,但是浏览器会显示滚动条以便查看其余的内容。
overflow: hidden: 内容会被修剪,并且其余内容是不可见的。
overflow: auto:      如果内容被修剪,则浏览器会显示滚动条以便查看其余的内容。
overflow: visible (默认): 默认值。内容不会被修剪,会呈现在元素框之外。
</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>

    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>overflow: scroll:<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="test1"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
      小学生优秀作文《当领导的好处》
      爸爸当上领导后,从来不敢多说话,生怕给别人带来压力。
      上个月,下属小李叔叔到我家来玩,爸爸随口说了句:“家里没空调,比较热,见笑了。”
      第二天,小李叔叔就带着师傅给我家安装了5匹的大空调!说什么也不肯收钱。
      上个星期,爸爸看到老张伯伯在办公室吃午饭,菜中有煎鱼,随口说了句:“哎呦,真香!”
      当天晚上,老张伯伯给我家送了一箱鲜鱼来。
      有一天晚上,我跟爸爸遛弯儿,路上碰到单位的小王叔叔和他媳妇逛街,爸爸随口称赞道:“哎呦,小王,你媳妇真漂亮!”
      第二天晚上,妈妈不在家,突然听到有人敲门。打开门一看,小王叔叔的媳妇站在门口,见到爸爸就满脸微笑说:“领导,我们家小王说嫂子不在家,让我来陪陪你!”
      当领导真好,怪不得这么多人喜欢当领导!
    </span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>overflow: hidden:<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="test2"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
      小学生优秀作文《当领导的好处》
      爸爸当上领导后,从来不敢多说话,生怕给别人带来压力。
      上个月,下属小李叔叔到我家来玩,爸爸随口说了句:“家里没空调,比较热,见笑了。”
      第二天,小李叔叔就带着师傅给我家安装了5匹的大空调!说什么也不肯收钱。
      上个星期,爸爸看到老张伯伯在办公室吃午饭,菜中有煎鱼,随口说了句:“哎呦,真香!”
      当天晚上,老张伯伯给我家送了一箱鲜鱼来。
      有一天晚上,我跟爸爸遛弯儿,路上碰到单位的小王叔叔和他媳妇逛街,爸爸随口称赞道:“哎呦,小王,你媳妇真漂亮!”
      第二天晚上,妈妈不在家,突然听到有人敲门。打开门一看,小王叔叔的媳妇站在门口,见到爸爸就满脸微笑说:“领导,我们家小王说嫂子不在家,让我来陪陪你!”
      当领导真好,怪不得这么多人喜欢当领导!
    </span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>overflow: auto:<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="test3"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
      小学生优秀作文《当领导的好处》
      爸爸当上领导后,从来不敢多说话,生怕给别人带来压力。
      上个月,下属小李叔叔到我家来玩,爸爸随口说了句:“家里没空调,比较热,见笑了。”
      第二天,小李叔叔就带着师傅给我家安装了5匹的大空调!说什么也不肯收钱。
      上个星期,爸爸看到老张伯伯在办公室吃午饭,菜中有煎鱼,随口说了句:“哎呦,真香!”
      当天晚上,老张伯伯给我家送了一箱鲜鱼来。
      有一天晚上,我跟爸爸遛弯儿,路上碰到单位的小王叔叔和他媳妇逛街,爸爸随口称赞道:“哎呦,小王,你媳妇真漂亮!”
      第二天晚上,妈妈不在家,突然听到有人敲门。打开门一看,小王叔叔的媳妇站在门口,见到爸爸就满脸微笑说:“领导,我们家小王说嫂子不在家,让我来陪陪你!”
      当领导真好,怪不得这么多人喜欢当领导!
    </span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>overflow: visible (默认):<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="test4"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="color: rgba(0, 0, 0, 1)">
      小学生优秀作文《当领导的好处》
      爸爸当上领导后,从来不敢多说话,生怕给别人带来压力。
      上个月,下属小李叔叔到我家来玩,爸爸随口说了句:“家里没空调,比较热,见笑了。”
      第二天,小李叔叔就带着师傅给我家安装了5匹的大空调!说什么也不肯收钱。
      上个星期,爸爸看到老张伯伯在办公室吃午饭,菜中有煎鱼,随口说了句:“哎呦,真香!”
      当天晚上,老张伯伯给我家送了一箱鲜鱼来。
      有一天晚上,我跟爸爸遛弯儿,路上碰到单位的小王叔叔和他媳妇逛街,爸爸随口称赞道:“哎呦,小王,你媳妇真漂亮!”
      第二天晚上,妈妈不在家,突然听到有人敲门。打开门一看,小王叔叔的媳妇站在门口,见到爸爸就满脸微笑说:“领导,我们家小王说嫂子不在家,让我来陪陪你!”
      当领导真好,怪不得这么多人喜欢当领导!
    </span><span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>

<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<span class="cnblogs_code_collapse">overflow</span></div>
<p><img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190704175011730-1980048371.png" alt=""></p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<h3><strong>6 清除浮动的方式2</strong></h3>
<div class="cnblogs_code"><img id="code_img_closed_05028402-9718-4a65-bde3-66e521ca737e" class="code_img_closed" src="https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif" alt=""><img id="code_img_opened_05028402-9718-4a65-bde3-66e521ca737e" class="code_img_opened" style="display: none" src="https://images.cnblogs.com/OutliningIndicators/ExpandedBlockStart.gif" alt="">
<div id="cnblogs_code_open_05028402-9718-4a65-bde3-66e521ca737e" class="cnblogs_code_hide">
<pre><span style="color: rgba(0, 0, 255, 1)">&lt;!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>清除浮动的方式1<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">style </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="text/css"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .top_bar</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">BFC区域 一条规则:计算BFC(块级盒子)的高度时,浮动元素也参与计算</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">形成BFC的条件: 除了overflow:visitable 的属性值</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span>
            <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">Block Formtting Context</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">*/</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            overflow</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> hidden</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            border</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 1px solid red</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .child1</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> green</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> left</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .child2</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 200px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> orange</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            float</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> right</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
      .header</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">{</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            width</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100%</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            height</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> 100px</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(255, 0, 0, 1)">
            background-color</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">:</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 255, 1)"> purple</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">;</span>
      <span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 0, 0, 1)">}</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="top_bar clearfix"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="child1"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>儿子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="child2"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>二儿子<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
    <span style="color: rgba(0, 0, 255, 1)">&lt;</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="header"</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
      
    <span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span>
<span style="color: rgba(0, 0, 255, 1)">&lt;/</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">&gt;</span></pre>
</div>
<span class="cnblogs_code_collapse">清除浮动的方式2</span></div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;<img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190704175101952-1458607671.png" alt=""></p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<h3><strong><span style="font-size: 14pt; font-family: 隶书">7 小米导航示例</span></strong></h3>
<div class="cnblogs_code"><img id="code_img_closed_92a2ae83-d05a-42a0-b630-777975cf180c" class="code_img_closed" src="https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif" alt=""><img id="code_img_opened_92a2ae83-d05a-42a0-b630-777975cf180c" class="code_img_opened" style="display: none" src="https://images.cnblogs.com/OutliningIndicators/ExpandedBlockStart.gif" alt="">
<div id="cnblogs_code_open_92a2ae83-d05a-42a0-b630-777975cf180c" class="cnblogs_code_hide">
<pre>&lt;!DOCTYPE html&gt;
&lt;html&gt;
&lt;head&gt;
    &lt;meta charset=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">utf-8</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
    &lt;title&gt;小米导航2&lt;/title&gt;
    &lt;link rel=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">stylesheet</span><span style="color: rgba(128, 0, 0, 1)">"</span> type=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">text/css</span><span style="color: rgba(128, 0, 0, 1)">"</span> href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">css/reset.css</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
    &lt;style type=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">text/css</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;<span style="color: rgba(0, 0, 0, 1)">
      .site</span>-<span style="color: rgba(0, 0, 0, 1)">header {
            height: 100px;
            width: </span>100%<span style="color: rgba(0, 0, 0, 1)">;
            </span>/*background-color: red;*/<span style="color: rgba(0, 0, 0, 1)">
      }
      .site</span>-<span style="color: rgba(0, 0, 0, 1)">header .container {
            </span>/*background-color: green;*/<span style="color: rgba(0, 0, 0, 1)">
            width: 1226px;
            margin: 0 auto;
      }

      .container .logo {
            float: left;
            margin</span>-<span style="color: rgba(0, 0, 0, 1)">top: 25px;
      }
      .logo a {
            display: block;
            height: 56px;
            width: 56px;
      }

      .site</span>-header .nav-<span style="color: rgba(0, 0, 0, 1)">list{
            float: left;
            width: 820px;
            height: 88px;
            padding: 12px 0 0 30px;
      }

      .nav</span>-<span style="color: rgba(0, 0, 0, 1)">list li {
            float: left;
            font</span>-<span style="color: rgba(0, 0, 0, 1)">size: 16px;
      }
      .nav</span>-<span style="color: rgba(0, 0, 0, 1)">listli a {
            display: block;
            color: </span><span style="color: rgba(0, 128, 0, 1)">#</span><span style="color: rgba(0, 128, 0, 1)">333;</span>
<span style="color: rgba(0, 0, 0, 1)">            padding: 28px 10px 38px;
      }

      .clearfix::after{
            content:</span><span style="color: rgba(128, 0, 0, 1)">''</span><span style="color: rgba(0, 0, 0, 1)">;
            clear: both;
            display: block;
      }

      .site</span>-<span style="color: rgba(0, 0, 0, 1)">search {
            float: right;
            width: 296px;
            margin</span>-<span style="color: rgba(0, 0, 0, 1)">top: 25px;
      }
      .site</span>-<span style="color: rgba(0, 0, 0, 1)">searchform {
            position: relative;
            height: 50px;
            width: 296px;
      }
      .site</span>-<span style="color: rgba(0, 0, 0, 1)">search form input.content{
            width: 223px;
            height: 48px;
            border: 1px solid </span><span style="color: rgba(0, 128, 0, 1)">#</span><span style="color: rgba(0, 128, 0, 1)">e0e0e0;</span>
<span style="color: rgba(0, 0, 0, 1)">            padding: 0 10px;
            float: left;
      }
      .site</span>-<span style="color: rgba(0, 0, 0, 1)">search form input.search {
            width: 49px;
            height: 50px;
            border: 1px solid </span><span style="color: rgba(0, 128, 0, 1)">#</span><span style="color: rgba(0, 128, 0, 1)">e0e0e0;</span>
<span style="color: rgba(0, 0, 0, 1)">            float: left;
            font</span>-<span style="color: rgba(0, 0, 0, 1)">size: 20px;
            margin</span>-left: -<span style="color: rgba(0, 0, 0, 1)">1px;
      }

      .nav</span>-<span style="color: rgba(0, 0, 0, 1)">list li a:active{
            color:orange;
      }

    </span>&lt;/style&gt;
&lt;/head&gt;
&lt;body&gt;
    &lt;div <span style="color: rgba(0, 0, 255, 1)">class</span>=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">site-header</span><span style="color: rgba(128, 0, 0, 1)">"</span> &gt;
      &lt;div <span style="color: rgba(0, 0, 255, 1)">class</span>=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">container clearfix</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
            
            &lt;div <span style="color: rgba(0, 0, 255, 1)">class</span>=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">logo</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
                &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
                  &lt;img src=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">images/logo.png</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
                &lt;/a&gt;   
            &lt;/div&gt;
            &lt;ul <span style="color: rgba(0, 0, 255, 1)">class</span>=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">nav-list</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;小米手机&lt;/a&gt;
                &lt;/li&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;Redmi 红米&lt;/a&gt;
                &lt;/li&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;电视&lt;/a&gt;
                &lt;/li&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;笔记本&lt;/a&gt;
                &lt;/li&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;家电&lt;/a&gt;
                &lt;/li&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;路由器&lt;/a&gt;
                &lt;/li&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;智能硬件&lt;/a&gt;
                &lt;/li&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;服务&lt;/a&gt;
                &lt;/li&gt;
                &lt;li&gt;
                  &lt;a href=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">#</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;社区&lt;/a&gt;
                &lt;/li&gt;
            &lt;/ul&gt;
            &lt;div <span style="color: rgba(0, 0, 255, 1)">class</span>=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">site-search</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
                &lt;form&gt;
                  &lt;input type=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">text</span><span style="color: rgba(128, 0, 0, 1)">"</span> name=<span style="color: rgba(128, 0, 0, 1)">""</span> <span style="color: rgba(0, 0, 255, 1)">class</span>=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">content</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
                  &lt;input type=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">submit</span><span style="color: rgba(128, 0, 0, 1)">"</span> name=<span style="color: rgba(128, 0, 0, 1)">""</span> value=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">搜索</span><span style="color: rgba(128, 0, 0, 1)">"</span> <span style="color: rgba(0, 0, 255, 1)">class</span>=<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">search</span><span style="color: rgba(128, 0, 0, 1)">"</span>&gt;
                &lt;/form&gt;
            &lt;/div&gt;


      &lt;/div&gt;
    &lt;/div&gt;
&lt;/body&gt;
&lt;/html&gt;</pre>
</div>
<span class="cnblogs_code_collapse">小米导航栏</span></div>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p><img src="https://img2018.cnblogs.com/blog/1050792/201907/1050792-20190709162529569-1334211329.png" alt=""></p>
<p>&nbsp;</p><br><br>
来源:https://www.cnblogs.com/augustyang/p/11126304.html
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