什麼是響應式 Web 設計？
1.RWD 指的是響應式 Web 設計（Responsive Web Design）
2.RWD 能夠以可變尺寸傳遞網頁
3.RWD 對於平板和移動設備是必需的
創建您自己的響應式設計
創建響應式設計的一個方法，是自己來創建它：
<!DOCTYPE html>
<html lang="en-US">
<head>
<style>
.city {
float: left;
margin: 5px;
padding: 15px;
width: 300px;
height: 300px;
border: 1px solid black;
}
</style>
</head>
<body>
<h1>W3School Demo</h1>
<h2>Resize this responsive page!</h2>
<br>
<div class="city">
<h2>London</h2>
<p>London 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>
使用 Bootstrap
另一個創建響應式設計的方法，是使用現成的 CSS 框架。
Bootstrap 是最流行的開發響應式 web 的 HTML, CSS, 和 JS 框架。
Bootstrap 幫助您開發在任何尺寸都外觀出衆的站點：顯示器、筆記本電腦、平板電腦或手機：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet"
href="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
</head>
<body>
<div class="container">
<div class="jumbotron">
<h1>W3School Demo</h1>
<p>Resize this responsive page!</p>
</div>
</div>
<div class="container">
<div class="row">
<div class="col-md-4">
<h2>London</h2>
<p>London 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="col-md-4">
<h2>Paris</h2>
<p>Paris is the capital and most populous city of France.</p>
</div>
<div class="col-md-4">
<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>
</div>
</div>
</body>
</html>