bootstrap3でのハンバーガーメニューの実装がうまくいきません

前提・実現したいこと

bootstrap3でハンバーガーメニューを作成しましたが開かず困っています。

発生している問題・エラーメッセージ

<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>わかまつ</title> <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css" rel="stylesheet"> <link href="style.css" rel="stylesheet" type="text/css">

<!--[if lt IE 9]>
  <script src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script>
  <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
<![endif]-->

</head> <body> <div class="navbar navbar-default"> <div class="container"> <div class="navbar-header"> <button type="button" class="navbar-toggle collapsed" data-taggle="collapse" data-target="#theNav" aria-expanded="false"> <span class="sr-only">Toggle navigation</span> <span class="icon-bar"></span> <span class="icon-bar"></span> <span class="icon-bar"></span> </button> <a class="navbar-brand" href="index.html">わかまつ</a> </div> <div class="collapse navbar-collapse" id="theNav"> <ul class="nav navbar-nav navbar-right"> <li class="active"><a href="index.html">Home</a></li> <li><a href="index.html">About</a></li> <li> <a href="videos.html" class="dropdown-toggle" data-taggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Videos <span class="caret"></span></a> <ul class="dropdown-menu"> <li><a href="videos.html">2017</a></li> <li><a href="videos.html">2016</a></li> <li><a href="videos.html">2015</a></li> <li><a href="videos.html">2014</a></li> </ul> </li> </ul> </div> </div> </div> <div class="container"> <div class="jumbotron text-center"> <h2>I am currently...</h2> <h1>わかまつ</h1> <h2>...until Septenber 1st</h2> </div> <h1 class="text-center">This Year's Video</h1> <br> <div class="embed-responsive embed-responsive-16by9"> <iframe src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d26056.2120651149!2d139.1128890015938!3d35.28046718278936!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x6019a402127b90f3%3A0x36683dedd897d3c4!2z5bCP55Sw5Y6f44OV44Op44Ov44O844Ks44O844OH44Oz!5e0!3m2!1sja!2sjp!4v1633873773789!5m2!1sja!2sjp" width="600" height="450" style="border:0;" allowfullscreen="" loading="lazy"></iframe> </div> </div> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script> </body> </html>