HTML 类¶

对 HTML 进行分类（设置类），使我们能够为元素的类定义 CSS 样式。

为相同的类设置相同的样式，或者为不同的类设置不同的样式。

<!DOCTYPE html>
<html>
<head>
<style>
.cities {
    background-color:black;
    color:white;
    margin:20px;
    padding:20px;
} 
</style>
</head>

<body>

<div class="cities">
<h2>London</h2>
<p>
London is the capital city of England. 
It is the most populous city in the United Kingdom, 
with a metropolitan area of over 13 million inhabitants.
</p>
</div> 

</body>
</html>

分类块级元素¶

HTML /

元素是块级元素。它能够用作其他 HTML 元素的容器。

设置 /

元素的类，使我们能够为相同的 /

元素设置相同的类：

<!DOCTYPE html>
<html>
<head>
<style>
.cities {
    background-color:black;
    color:white;
    margin:20px;
    padding:20px;
} 
</style>
</head>

<body>

<div class="cities">
<h2>London</h2>
<p>London is the capital city of England. 
It is the most populous city in the United Kingdom, 
with a metropolitan area of over 13 million inhabitants.</p>
</div>

<div class="cities">
<h2>Paris</h2>
<p>Paris is the capital and most populous city of France.</p>
</div>

<div class="cities">
<h2>Tokyo</h2>
<p>Tokyo is the capital of Japan, the center of the Greater Tokyo Area,
and the most populous metropolitan area in the world.</p>
</div>

</body>
</html>

分类行内元素¶

HTML / 元素是行内元素，能够用作文本的容器。

设置 / 元素的类，能够为相同的 / 元素设置相同的样式。

<!DOCTYPE html>
<html>
<head>
<style>
  span.red {color:red;}
</style>
</head>
<body>

<h1>My <span class="red">Important</span> Heading</h1>

</body>
</html>