How do I cover the Bootstrap modal backdrop on the whole screen? - html

Question

Scenario
I tried to cover backdrop on the whole screen but when I open my modal backdrop, the start from the header stays out of my modal backdrop. How can I cover the backdrop on the whole screen?
Modal HTML
<div class="modal fade" id="modalDetailFormalite" tabindex="-1" role="dialog" aria-hidden="true">
<div class="modal-dialog modal-lg" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title" id="contact">Détails</h5>
<button type="button" class="close" aria-label="Close" onclick="hideModalDetailFormalite()">
<span aria-hidden="true">×</span>
</button>
</div>
<div class="modal-body">
<div class="row" id="detailsFlows">
</div>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-common" id="btnAddToCardDocFlows" disabled="disabled">
<i class='fa fa fa-cart-plus' id="iconBtnAddToCardDocFlows"></i> Ajouter au panier
</button>
<button type="button" class="btn btn-secondary" id="btnCloseModalDetailFormalite" onclick="hideModalDetailFormalite()">Fermer</button>
</div>
</div>
</div>
</div>
Navbat HTML
<nav class="navbar navbar-expand-lg fixed-top scrolling-navbar">
<div class="container">
<div class="theme-header clearfix">
<div class="navbar-header">
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#main-navbar" aria-controls="main-navbar" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
<span class="lni-menu"></span>
<span class="lni-menu"></span>
<span class="lni-menu"></span>
</button>
<img src="assets/img/logo.png" alt="">
</div>
<div class="collapse navbar-collapse" id="main-navbar">
<ul class="navbar-nav mr-auto w-100 justify-content-end" id="nav">
<li class="nav-item">
<a class="nav-link" href="index.html">
Accueil
</a>
</li>
<li class="nav-item">
<a class="nav-link" href="apropos.html">
A Propos
</a>
</li>
<li class="nav-item">
<a class="nav-link" href="contact.html">
Contact
</a>
</li>
<li class="nav-item">
<a class="nav-link" href="inscription.html">S'inscrire</a>
</li>
<li class="button-group">
<i class="lni-user"></i> Se connecter
</li>
</ul>
</div>
</div>
</div>
<div class="mobile-menu" data-logo="assets/img/logo.png"></div>
Here is what the view looks like when I call my modal

Answer 1

It is problem of z-index in navigation bar
add below CSS in your project, replace navbar class with your main navigation bar class
.modal-open .navbar {
z-index: 1100;
}

Answer 2

I just found the solution, which consisted in removing the z-index:999999 in my main.css file and leaving just the one in bootstrap.css z-index: 1030