Html 手机上的导航菜单很古怪？

我试图简化我客户网站背后的代码，因为有一些无关的代码。执行此操作时，导航菜单（引导）不再工作？它似乎是屏幕外的，我不知道为什么或如何修复它

<div id="container-para" class="container-fluid">
  <nav class="navbar navbar-default navbar-toggleable-md navbar-expand-lg navbar-inverse bg-inverse justify-content-around fixed-top" >
        <a class="navbar-brand" href="/">    
        <img src="/inc/img/IMG_1877.jpg" alt="Cheapest Used Tires" style="padding-right:1px;border-radius: 6%;"><span>Cheapest Used Tires</span></a>
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavAltMarkup"
                aria-controls="navbarNavAltMarkup" aria-expanded="false" aria-label="Toggle navigation">
            <img class="logo3" src="/inc/img/3logo.jpg">
        </button>

        <div class="collapse navbar-collapse" id="navbarNavAltMarkup">

            <ul class="navbar-nav navbar-justify text-center">

    <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="dealersDropdown" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        <img class="logo3" src="/inc/img/3logo.jpg">
Tire Dealers</a>
        <div class="dropdown-menu" aria-labelledby="dealersDropdown">
            <a class="dropdown-item" href="/tire-dealers.php">Tire Dealers</a>
                        <a class="dropdown-item" href="/construction.php">Tire Services</a>
                        <a class="dropdown-item" href="/construction.php">All Auto Services</a>
            </div>  
        </li>

    <li class="nav-item">
        <a class="nav-link" href="/construction.php">Why Used?</a>
    </li>

    <li class="nav-item">
        <a class="nav-link" href="/construction.php">Tire Science</a>
    </li>

    <li class="nav-item">
        <a class="nav-link" href="/construction.php">Tire Products</a>
    </li>
    <li class="nav-item">
        <a class="nav-link" href="/NewPages/contact.php">Contact Us</a>
    </li>
    <li class="nav-item">
        <form method="post" action="/auth/user/users.php">
            <button class="nav-item nav-link buttons">Login or Join</button>
        </form>
    </li>
</ul>
</div>
</nav>

登录或加入

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Bootstrap3代码确实不适用于Bootstrap4CSS。引导程序4几乎是对引导程序3的完全重写。所以，几乎一切都改变了

以下是Bootstrap 4导航栏的工作原理：

搜索

您没有将引导程序4包含在小提琴中。