CSS学习（一）
<p>CSS（Cascading Style Sheets）称为层叠样式表，用于对页面进行美化。</p><h1>一、应用方式</h1>
<p>css的样式有很多种，当如果想要把css样式应用到特定标签上有三种方式：</p>
<h2>1.1 标签中填写</h2>
<p>适用范围：指定一个标签。【不推荐，多标签无法复用样式】</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div </span><span style="color: rgba(255, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">="color:green;"</span><span style="color: rgba(0, 0, 255, 1)">></span>KOBE<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
</div>
<p> </p>
<h2>1.2 head标签中定义</h2>
<p>适用范围：当前页面的所有标签。【推荐，多个标签可复用样式】</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">html </span><span style="color: rgba(255, 0, 0, 1)">lang</span><span style="color: rgba(0, 0, 255, 1)">="en"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>CSS学习<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 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)">给所有的div设置样式</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(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)">
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="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>Alex<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>mjj<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
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<p> </p>
<h2>1.3 在css文件中定义，适用范围：所有引入css文件的页面。</h2>
<p>适用范围：所有引入css文件的页面。【推荐，多页面、多个标签均可复用样式】</p>
<ul>
<li>创建css文件，如：common.css</li>
</ul>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 0, 1)">div {
color: green;
}</span></pre>
</div>
<ul>
<li>创建html文件，如：index.html</li>
</ul>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">html </span><span style="color: rgba(255, 0, 0, 1)">lang</span><span style="color: rgba(0, 0, 255, 1)">="en"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>CSS学习<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)"> href</span><span style="color: rgba(0, 0, 255, 1)">="common.css"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>Alex<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>老男孩<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
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<p>以后在企业中写应用css样式时，写单页面时会把样式写在head头部；写多页面时，会把样式写入css文件，然后再在要应用的html页面引入css即可。</p>
<h1>二、选择器</h1>
<p>学习选择器的目的就是选中html页面中指定标签，便于以后给他应用样式。</p>
<h2>2.1 标签选择器</h2>
<p>在body中找到所有指定标签，例如：找到所有a标签，让他们颜色变绿。</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">html </span><span style="color: rgba(255, 0, 0, 1)">lang</span><span style="color: rgba(0, 0, 255, 1)">="en"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>CSS学习<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 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)">
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="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>周杰伦<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">="https://www.oldboyedu.com"</span><span style="color: rgba(0, 0, 255, 1)">></span>Alex<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">></span>Alex<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>朗朗<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
</div>
<p> </p>
<h2>2.2 id选择器</h2>
<p>在body中找一个id匹配的标签。（HTML中ID属性应唯一，相当于人的身份证号码），例如：找到id等于i1的标签，让他颜色变绿。</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">html </span><span style="color: rgba(255, 0, 0, 1)">lang</span><span style="color: rgba(0, 0, 255, 1)">="en"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>CSS学习<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 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)">找到所有a标签，并应用内部数据</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)">
#i1 </span><span style="background-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)"> 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)"></</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>老男孩<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">span </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="i1"</span><span style="color: rgba(0, 0, 255, 1)">></span>师范<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">span</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">></span>南京<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
</div>
<p> </p>
<h2>2.3 class选择器</h2>
<p>在body中找到所有class属性值匹配的标签。例如：找到所有class等于head的标签，让他绿了。</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">html </span><span style="color: rgba(255, 0, 0, 1)">lang</span><span style="color: rgba(0, 0, 255, 1)">="en"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>CSS学习<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
.head </span><span style="background-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)"> 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)"></</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">="head"</span><span style="color: rgba(0, 0, 255, 1)">></span>老男孩<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">="http://www.sb.com"</span><span style="color: rgba(0, 0, 255, 1)">></span>李杰<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">p </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="head"</span><span style="color: rgba(0, 0, 255, 1)">></span>武沛齐<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
</div>
<p> </p>
<h2>2.4 属性选择器</h2>
<p>在body中找到所以class属性值匹配的标签。</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">html </span><span style="color: rgba(255, 0, 0, 1)">lang</span><span style="color: rgba(0, 0, 255, 1)">="en"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>CSS学习<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 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)"> 找到class=head并且name=boy的标签 </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)">
.head </span><span style="background-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)"> 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)"></</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">="head"</span><span style="color: rgba(255, 0, 0, 1)"> name</span><span style="color: rgba(0, 0, 255, 1)">="boy"</span> <span style="color: rgba(0, 0, 255, 1)">></span>老男孩<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">="http://www.sb.com"</span><span style="color: rgba(0, 0, 255, 1)">></span>李杰<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">p </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="head"</span><span style="color: rgba(255, 0, 0, 1)"> name</span><span style="color: rgba(0, 0, 255, 1)">="hanshuo"</span> <span style="color: rgba(0, 0, 255, 1)">></span>韩烁<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">p</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
</div>
<p> </p>
<h2>2.5 后代选择器</h2>
<p>在body标签中根据父子关系找到指定标签。</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">html </span><span style="color: rgba(255, 0, 0, 1)">lang</span><span style="color: rgba(0, 0, 255, 1)">="en"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>CSS学习<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(128, 0, 0, 1)">
.head ul .hat </span><span style="background-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)"> 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)"></</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>老男孩<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">="head"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="hat"</span><span style="color: rgba(0, 0, 255, 1)">></span>北京<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">></span>沙河<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">a </span><span style="color: rgba(255, 0, 0, 1)">class</span><span style="color: rgba(0, 0, 255, 1)">="hat"</span><span style="color: rgba(0, 0, 255, 1)">></span>沙河高晓松Alex<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>沙河大烧饼Alex<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">li</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">ul</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">="head"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>武沛齐<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">a</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
</div>
<p> </p>
<h2>2.6 选择器分组</h2>
<p>对选择器进行分组，无需重复编写。</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 255, 1)"><!</span><span style="color: rgba(255, 0, 255, 1)">DOCTYPE html</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">html </span><span style="color: rgba(255, 0, 0, 1)">lang</span><span style="color: rgba(0, 0, 255, 1)">="en"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>CSS学习<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">title</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 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)"> 不推荐写法 </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(0, 128, 0, 1)">/*</span><span style="background-color: rgba(245, 245, 245, 1); color: rgba(0, 128, 0, 1)">
h1 {
color: green;
}
.head h2{
color: green;
}
h3{
color: green;
}
h4{
color: green;
}
</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)">
h1, .head h2, h3, h4 </span><span style="background-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)"> 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)"></</span><span style="color: rgba(128, 0, 0, 1)">style</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">head</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">h1</span><span style="color: rgba(0, 0, 255, 1)">></span>kobe<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">h1</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</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)">="head"</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">></span>lebron<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">h2</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">div</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">h3</span><span style="color: rgba(0, 0, 255, 1)">></span>curry<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">h3</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">h4</span><span style="color: rgba(0, 0, 255, 1)">></span>james<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">h4</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">body</span><span style="color: rgba(0, 0, 255, 1)">></span>
<span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">html</span><span style="color: rgba(0, 0, 255, 1)">></span></pre>
</div>
<p> </p><br><br>
来源：https://www.cnblogs.com/sunny0824/p/13367432.html
頁:
[1]