Absolute positioning a bootstrap navbar interferes with alignment of items - html

Question

I am trying to create a navbar overtop a carousel. The navbar should have two sets of links;
1: Links aligned to the left
2: Social media links aligned to the right
I have have done this successfully with the code below;
HTML
<nav class="navbar navbar-expand-lg navbar-light bg-light" id = "navigation">
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link" href="#">GALLERIES <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">ABOUT</a>
</li>
</ul>
<ul class="navbar-nav ml-auto">
<li class="nav-item">
<a class="navbar-brand" href="#">
<img src="images/icons/shopping-cart.png" class = "nav_icon" alt = "">
</a>
</li>
<li class="nav-item">
<a class="navbar-brand" href="#">
<img src="images/icons/twitter.png" class = "nav_icon" alt = "">
</a>
</li>
</ul>
</div>
</nav>
CSS
#navigation{
z-index: 999;
background:0 !important;
font-size: 1.5vw;
color: #fff !important;
/*position: absolute;*/
}
.nav_icon{
width: 2vw;
height: 2vw;
}
This yields the following result;
However, I want the navbar to be overtop my carousel (code for the carousel not included).
Adding 'position: absolute' interferes with my alignment like so;
Why is this happening? How can I get the same results without messing up the alignment of the links?