问使用lead类设置段落样式

EN

<div class="example">
   <h1>Hello</h1>
</div>

<lead class="p"></lead>

<p class="lead"></p>

p{
  font-size: 20px;
}


p#hello-world {
  color: blue;
}

p.hello-world {
  color: red;
}

p.hello-world.italic {
  font-style: italic;
}

.bold{
  font-weight: bold;
}

#bye{
  text-decoration: underline;
}

<pre>p</pre>
<p>Hello World</p>

<pre>p#hello-world - p tag with id 'hello-world'</pre>
<p id="hello-world">Hello World</p>

<pre>p.hello-world - p tag with class 'hello-world'</pre>
<p class="hello-world">Hello World</p>

<pre>p.hello-world.italic - p tag with class 'hello-world' and italic</pre>
<p class="hello-world italic">Hello World</p>

<pre>.bold - any tag with class 'bold'</pre>
<div class="bold">Hello World</div>

<pre>#bye - any tag but only the first as id's should
be unique (use class instead if you want to target
multiple elements) with id 'bye'</pre>
<div id="bye">Hello World</div>