所以我折叠的导航栏拒绝工作，我尝试更改我的 CDN，认为它可能是旧版本，但无济于事，所以这是我的代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>lift Gym</title>
<!-- bootsrap style -->
<link
href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
rel="stylesheet"
integrity="sha384-T3c6CoIi6uLrA9TneNEoa7RxnatzjcDSCmG1MXxSR1GAsXEV/Dwwykc2MPK8M2HN"
crossorigin="anonymous"
/>
<!--- customized style in index.css -->
<link rel="stylesheet" href="index.css" />
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="container-fluid">
<a class="display1 navbar-brand" id="heading" href="#">lift Gym</a>
<button
class="navbar-toggler"
type="button"
data-bs-toggle="collapse"
data-bs-target="#navbarNav"
aria-controls="navbarNav"
aria-expanded="false"
aria-label="Toggle navigation"
>
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse">
<ul class="h4 navbar-nav ml-auto">
<li class="nav-item">
<a class="nav-link active ml-5 mr-5" aria-current="page" href="#"
>Home</a
>
</li>
<li class="nav-item">
<a class="nav-link ml-5 mr-5" href="#">about us </a>
</li>
<li class="nav-item">
<a class="nav-link ml-5 mr-5" href="#">Pricing</a>
</li>
<li class="nav-item">
<a class="nav-link ml-5 mr-3" href="#">contact us </a>
</li>
</ul>
</div>
</div>
</nav>
<footer class="py-5 mt-5 fixed-bottom" id="footerStyle"></footer>
<!-- bbotsrap js -->
<script
defer
src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js"
integrity="sha384-C6RzsynM9kWDrMNeT87bh95OGNyZPhcTNXj1NW7RuBCsyN/o0jlpcV8Qyq46cDfL"
crossorigin="anonymous"
></script>
</body>
</html>当我尝试点击我的折叠时，它没有反应，所以我假设三是 js 的东西 我试图修复我只是不知道感谢帮助
您没有 id 的目标
navbarNav<nav class="navbar navbar-expand-lg navbar-dark bg-dark" >
<div class="container-fluid">
<a class="display1 navbar-brand" id="heading" href="#">lift Gym</a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarNav">
<ul class="h4 navbar-nav ml-auto">
<li class="nav-item">
<a class="nav-link active ml-5 mr-5" aria-current="page" href="#">Home</a>
</li>
<li class="nav-item">
<a class="nav-link ml-5 mr-5" href="#">about us </a>
</li>
<li class="nav-item">
<a class="nav-link ml-5 mr-5" href="#">Pricing</a>
</li>
<li class="nav-item">
<a class="nav-link ml-5 mr-3" href="#">contact us </a>
</li>
</ul>
</div>
</div>
</nav>