<link rel="stylesheet" href="bootstrap.min.css" />

引入bootstrap.min.css檔案

<meta name="viewport" content="width=device-width,initial-scale=1" />

content="width=device-width：設為頁面自適應

initial-scale=1：縮放比例：當前不縮放

例1：

 寫頭部（navbar-fixed-top）底部（navbar-fixed-bottom）導航欄

<nav 
 
class="navbar navbar-default navbar-fixed-bottom" role="navigation">
            <div class="container">
                <!-- logo -->
                <div class="navbar-header">
                    <a href="#" class="navbar-brand">Projectname</a>
                </
 
div>
                <!-- 導航欄 -->
                <div id="navabar" class="collapse navbar-collapse">
                    <ul class="nav navbar-nav">
                        <li><a href="#">Home</a></li>
                        <li><a href="#">About</
 
a></li>
                        <li><a href="#">Contact</a></li>
                    </ul>
                </div>
            </div>
        </nav>