Full-width Bootstrap dropdown menu at hover disappears - html

Question

I have a full-width Bootstrap dropdown menu that is not working properly as it has a lot of space between the button and the menu.
So far I am only using CSS for this, no javascript. Here´s the code:
HTML:
<nav class="p-4 navbar navbar-expand-lg navbar-light bg-light">
<a class="navbar-brand" href="#">
<img src="http://lorempixel.com/30/30/abstract" width="30" height="30" class="d-inline-block align-top" alt="">
Shopstrap
</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarNavDropdown">
<ul class="navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Features</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Pricing</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Dropdown link
<i class="fas fa-angle-up"></i>
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
<li class="nav-item dropdown catalog">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Catalog
<i class="fas fa-angle-up"></i>
</a>
<div class="dropdown-menu catalog-menu" aria-labelledby="navbarDropdownMenuLink">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
</div>
</li>
</ul>
</div>
</nav>
CSS:
.navbar-default .navbar-nav > li.dropdown:hover > a,
.navbar-default .navbar-nav > li.dropdown:hover > a:hover,
.navbar-default .navbar-nav > li.dropdown:hover > a:focus {
background-color: rgb(231, 231, 231);
color: rgb(85, 85, 85);
}
li.dropdown:hover > .dropdown-menu {
display: block;
}
.navbar .dropdown.catalog {
position: static;
float: none;
}
.navbar .dropdown .dropdown-menu.catalog-menu{
width: 100%;
}
Fiddle:
https://jsfiddle.net/m4Lxugea/1/
I hope any of you can help me with this. I was thinking in maybe I can´t do this purely CSS but I need to add javascript for the hovering.
Alejandro.

Answer 1

The key CSS for you is:
li.dropdown:hover > .dropdown-menu {
display: block;
}
Which means that: while you're hovering over the 'Catalog' link in the navigation (on desktop), show the child .dropdown-menu and as soon as you hover away, the .dropdown-menu goes to its default state of display:none;
With JS you can add a class which makes sure that the .dropdown-menu stays open unless you click somewhere else to undo this

Answer 2

Here is solution: Bootstrap adds margin-top for each dropdown-menu class.
Make it 0px;
Bootstrap has padding on navbar class, Also make override it to 0px;
Here is working example https://bootstrap-menu.com/detail-megamenu.html
navbar{ padding-top: 0; padding-bottom: 0; }
navbar .has-megamenu{position:static!important;}
navbar .megamenu{left:0; right:0; width:100%; padding:20px; }
navbar .nav-link{ padding-top:1rem; padding-bottom:1rem; }