我复制了Bulma的basic starter template和basic navbar。然而，当我点击汉堡包菜单时，没有任何反应:(。我错过了什么吗？你可以try it in my jsfiddle：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Hello Bulma!</title>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bulma/0.7.4/css/bulma.min.css">
<script defer src="https://use.fontawesome.com/releases/v5.3.1/js/all.js"></script>
</head>
<body>
<nav class="navbar" role="navigation" aria-label="main navigation">
<div class="navbar-brand">
<a class="navbar-item" href="https://bulma.io">
<img src="https://bulma.io/images/bulma-logo.png" width="112" height="28">
</a>
<a role="button" class="navbar-burger burger" aria-label="menu" aria-expanded="false" data-target="navbarBasicExample">
<span aria-hidden="true"></span>
<span aria-hidden="true"></span>
<span aria-hidden="true"></span>
</a>
</div>
<div id="navbarBasicExample" class="navbar-menu">
<div class="navbar-start">
<a class="navbar-item">
Home
</a>
<a class="navbar-item">
Documentation
</a>
<div class="navbar-item has-dropdown is-hoverable">
<a class="navbar-link">
More
</a>
<div class="navbar-dropdown">
<a class="navbar-item">
About
</a>
<a class="navbar-item">
Jobs
</a>
<a class="navbar-item">
Contact
</a>
<hr class="navbar-divider">
<a class="navbar-item">
Report an issue
</a>
</div>
</div>
</div>
<div class="navbar-end">
<div class="navbar-item">
<div class="buttons">
<a class="button is-primary">
<strong>Sign up</strong>
</a>
<a class="button is-light">
Log in
</a>
</div>
</div>
</div>
</div>
</nav>
<section class="section">
<div class="container">
<h1 class="title">
Hello World
</h1>
<p class="subtitle">
My first website with <strong>Bulma</strong>!
</p>
</div>
</section>
</body>
</html>