移动端Navbar点击无响应求助：无法正常展开/收起

问题说明 #

开发HTML网站时，移动端视图下Navbar点击后无响应，无法正常展开或收起，需要实现点击Navbar可展开、再次点击可收起的功能。

用户提供代码 #

HTML代码 #

<!-- ======= Header ======= -->
<header id="header" class="d-flex align-items-center">
  <div class="container d-flex align-items-center justify-content-between">
      <img src="assets/img/logo.jpg" class="" alt="">
    <h1 class="logo"><a href="index.html">...</a></h1>
    <!-- Uncomment below if you prefer to use an image logo -->
    <!-- <a href="index.html" class="logo"><img src="assets/img/logo.png" alt=""></a>-->
    

    <nav id="navbar" class="navbar">
          
      <ul>
        <li><a class="nav-link scrollto active" href="index.html">Home</a></li>
        <li><a class="nav-link scrollto" href="#about">About</a></li>
        <li><a class="nav-link scrollto" href="service.html">Services</a></li>
        <li><a class="nav-link scrollto " href="portfolio.html">Portfolio</a></li>
        <li><a class="nav-link scrollto" href="team.html">Team</a></li>
        <li><a class="nav-link scrollto" href="contact.html">Contact</a></li>
      </ul>
      <i class="bi bi-list mobile-nav-toggle"></i>
    </nav><!-- .navbar -->

  </div>
</header><!-- End Header -->

CSS代码 #

/*--------------------------------------------------------------
# Navigation Menu
--------------------------------------------------------------*/
/**
* Desktop Navigation 
*/
.navbar {
  padding: 0;
}

.navbar ul {
  margin: 0;
  padding: 0;
  display: flex;
  list-style: none;
  align-items: center;
}

.navbar li {
  position: relative;
}

.navbar>ul>li {
  white-space: nowrap;
  padding: 10px 0 10px 28px;
}

.navbar a,
.navbar a:focus {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 3px;
  font-size: 15px;
  font-weight: 600;
  color: #222222;
  white-space: nowrap;
  transition: 0.3s;
  position: relative;
}

.navbar a i,
.navbar a:focus i {
  font-size: 12px;
  line-height: 0;
  margin-left: 5px;
}

.navbar>ul>li>a:before {
  content: "";
  position: absolute;
  width: 100%;
  height: 2px;
  bottom: -6px;
  left: 0;
  background-color: #106eea;
  visibility: hidden;
  width: 0px;
  transition: all 0.3s ease-in-out 0s;
}

.navbar a:hover:before,
.navbar li:hover>a:before,
.navbar .active:before {
  visibility: visible;
  width: 100%;
}

.navbar a:hover,
.navbar .active,
.navbar .active:focus,
.navbar li:hover>a {
  color: #106eea;
}

.navbar .dropdown ul {
  display: block;
  position: absolute;
  left: 28px;
  top: calc(100% + 30px);
  margin: 0;
  padding: 10px 0;
  z-index: 99;
  opacity: 0;
  visibility: hidden;
  background: #fff;
  box-shadow: 0px 0px 30px rgba(127, 137, 161, 0.25);
  transition: 0.3s;
}

.navbar .dropdown ul li {
  min-width: 200px;
}

.navbar .dropdown ul a {
  padding: 10px 20px;
  font-weight: 400;
}

.navbar .dropdown ul a i {
  font-size: 12px;
}

.navbar .dropdown ul a:hover,
.navbar .dropdown ul .active:hover,
.navbar .dropdown ul li:hover>a {
  color: #106eea;
}

.navbar .dropdown:hover>ul {
  opacity: 1;
  top: 100%;
  visibility: visible;
}

.navbar .dropdown .dropdown ul {
  top: 0;
  left: calc(100% - 30px);
  visibility: hidden;
}

.navbar .dropdown .dropdown:hover>ul {
  opacity: 1;
  top: 0;
  left: 100%;
  visibility: visible;
}

@media (max-width: 1366px) {
  .navbar .dropdown .dropdown ul {
    left: -90%;
  }

  .navbar .dropdown .dropdown:hover>ul {
    left: -100%;
  }
}

/**
* Mobile Navigation 
*/
.mobile-nav-toggle {
  color: #222222;
  font-size: 28px;
  cursor: pointer;
  display: none;
  line-height: 0;
  transition: 0.5s;
}

.mobile-nav-toggle.bi-x {
  color: #fff;
}

@media (max-width: 991px) {
  .mobile-nav-toggle {
    display: block;
  }

  .navbar ul {
    display: none;
  }
}

.navbar-mobile {
  position: fixed;
  overflow: hidden;
  top: 0;
  right: 0;
  left: 0;
  bottom: 0;
  background: rgba(9, 9, 9, 0.9);
  transition: 0.3s;
  z-index: 999;
}

.navbar-mobile .mobile-nav-toggle {
  position: absolute;
  top: 15px;
  right: 15px;
}

.navbar-mobile ul {
  display: block;
  position: absolute;
  top: 55px;
  right: 15px;
  bottom: 15px;
  left: 15px;
  padding: 10px 0;
  background-color: #fff;
  overflow-y: auto;
  transition: 0.3s;
}

.navbar-mobile a,
.navbar-mobile a:focus {
  padding: 10px 20px;
  font-size: 15px;
  color: #222222;
}

.navbar-mobile>ul>li {
  padding: 0;
}

.navbar-mobile a:hover:before,
.navbar-mobile li:hover>a:before,
.navbar-mobile .active:before {
  visibility: hidden;
}

.navbar-mobile a:hover,
.navbar-mobile .active,
.navbar-mobile li:hover>a {
  color: #106eea;
}

.navbar-mobile .getstarted,
.navbar-mobile .getstarted:focus {
  margin: 15px;
}

.navbar-mobile .dropdown ul {
  position: static;
  display: none;
  margin: 10px 20px;
  padding: 10px 0;
  z-index: 99;
  opacity: 1;
  visibility: visible;
  background: #fff;
  box-shadow: 0px 0px 30px rgba(127, 137, 161, 0.25);
}

.navbar-mobile .dropdown ul li {
  min-width: 200px;
}

.navbar-mobile .dropdown ul a {
  padding: 10px 20px;
}

.navbar-mobile .dropdown ul a i {
  font-size: 12px;
}

.navbar-mobile .dropdown ul a:hover,
.navbar-mobile .dropdown ul .active:hover,
.navbar-mobile .dropdown ul li:hover>a {
  color: #106eea;
}

.navbar-mobile .dropdown>.dropdown-active {
  display: block;
}

.navbar-mobile a:hover:before,
.navbar-mobile li:hover>a:before,
.navbar-mobile .active:before {
  visibility: hidden;
}

.navbar-mobile a:hover,
.navbar-mobile .active,
.navbar-mobile li:hover>a {
  color: #106eea;
}

.navbar-mobile .getstarted,
.navbar-mobile .getstarted:focus {
  margin: 15px;
}

.navbar-mobile .dropdown ul {
  position: static;
  display: none;
  margin: 10px 20px;
  padding: 10px 0;
  z-index: 99;
  opacity: 1;
  visibility: visible;
  background: #fff;
  box-shadow: 0px 0px 30px rgba(127, 137, 161, 0.25);
}

.navbar-mobile .dropdown ul li {
  min-width: 200px;
}

.navbar-mobile .dropdown ul a {
  padding: 10px 20px;
}

.navbar-mobile .dropdown ul a i {
  font-size: 12px;
}

.navbar-mobile .dropdown ul a:hover,
.navbar-mobile .dropdown ul .active:hover,
.navbar-mobile .dropdown ul li:hover>a {
  color: #106eea;
}

.navbar-mobile .dropdown>.dropdown-active {
  display: block;
}

修复方案 #

1. 添加JavaScript交互逻辑 #

问题核心是缺少触发样式切换的JS代码，CSS已定义移动端导航的显示样式，但没有代码控制.navbar-mobile类的添加/移除。在页面底部</body>标签前插入以下代码：

document.addEventListener('DOMContentLoaded', function() {
  const mobileNavToggle = document.querySelector('.mobile-nav-toggle');
  const navbar = document.getElementById('navbar');

  if (mobileNavToggle && navbar) {
    // 点击切换导航展开/收起
    mobileNavToggle.addEventListener('click', function() {
      navbar.classList.toggle('navbar-mobile');
      // 切换图标（列表/叉号）
      this.classList.toggle('bi-list');
      this.classList.toggle('bi-x');
    });

    // 点击导航链接自动收起菜单
    const navLinks = navbar.querySelectorAll('.nav-link');
    navLinks.forEach(link => {
      link.addEventListener('click', function() {
        if (navbar.classList.contains('navbar-mobile')) {
          navbar.classList.remove('navbar-mobile');
          mobileNavToggle.classList.add('bi-list');
          mobileNavToggle.classList.remove('bi-x');
        }
      });
    });
  }
});

2. 清理重复CSS代码 #

提供的CSS中重复定义了.navbar-mobile相关样式，需删除重复部分，仅保留一份，避免样式冲突导致的异常。

3. 验证Bootstrap Icons引入 #

确保页面<head>中已引入Bootstrap Icons，否则bi-list和bi-x图标无法显示：

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.10.0/font/bootstrap-icons.css">

内容的提问来源于stack exchange，提问作者richie