一、HTML创建响应设计 Responsive Web Design 可以改变尺寸传递网页，对于平板和移动设备是必须的
1、<!DOCTYPE html>
<html lang="en-US>
<head>
<style>
.city{
float:left;
margin:5px;
padding:15px;
300px;
height:300px;
broder: 1px solid black;}
</style>
</head>
<body>
<h1>W3cSchool<h1>
<h2>Resize this responsive page</h2>
<br/>
<div class="city">
<h2>London</h2>
<p>It is the capital city of England</p>
<p>It is the most populous city in the United Kingdom,
with a metropolitan area of over 13 million inhabitants.</p>
</div>
<div class="city">
<h2>Paris</h2>
<p>Paris is the capital and most populous city of France.</p>
</div>
<div class="city">
<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>
2、使用Bootstrap 使用现成的CSS框架 开发响应式Web的Html CSS JS 框架