I have html code, when I resize the browser screen I have a problem that the toggle button is not displayed (it is transparent) when I click on it the navigation bar items are not showing at allScreenshot of my web
<html>
    <head>
        <title>
            profile 
        </title>
        <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <!-- Bootstrap CSS-->
        <link rel="stylesheet" href="../css/bootstrap/bootstrap.css">
        <!-- w3 CSS-->
        <link rel="stylesheet" href="../css/W3.css">
         <!-- profile CSS-->
         <link rel="stylesheet" href="../css/accueil.css">
        <!-- flaticon CSS-->
        <link rel="stylesheet" href="../icons/font/flaticon.css">
        <!--Scripts-->
        <!-- JQuery script-->
        <script src="../js/jQuery.js"></script>
        <!-- Bootstrap script-->
        <script src="../js/bootstrap/bootstrap.bundle.min.js"></script>
    </head>
    <body>
        <header>
            <nav class="navbar navbar-expand-md fixed-top">
                <div class="container-fluid">
                    <a class="navbar-brand" href="accueil.html">
                        <h4>LOGO</h4>
                    </a>
                    <!--Collapse button -->
                    <button type="button" class="navbar-toggler" 
                    data-bs-toggle="collapse" data-bs-target="#coll_target"
                    aria-controls="coll_target" aria-expanded="false"
                    aria-label="Toggle Navbar" >
                        <span class="navbar-toggler-icon" ></span>
                    </button>
                    <!--Collapse Div -->
                    <div class="collapse navbar-collapse" id="coll_target">
                        <div class="mx-auto"></div>
                        <ul class="navbar-nav ml-auto">
                            <li class="nav-item"><a class="nav-link"><span><i class="flaticon-ringing" style="color: white;"></i></span></a></li>
                            <li class="nav-item"><a class="nav-link"><span><i class="flaticon-email" style="color: white;"></i></span></a></li>
                            <li class="nav-item"><a class="nav-link"><span><i style="color: white;" class="flaticon-down-arrow"></i></span></a></li>
                            <li class="nav-item"><a class="nav-link"><span><i style="color: white;" class="flaticon-translation"></i></span></a></li>
                            <li class="nav-item"><a class="nav-link"><span><i class="flaticon-settings" style="color: white;"></i></span></a></li>
                        </ul>
                    </div>
                </div>
            </nav>
        </header>
           
    </body>
</html> 
    