Remove spacing between navbar and image - html

Question

I have a Navbar with logo and links spaced out appropriately, in the hero section I use an image with full width and height but if leaves a white space between the nav and hero section. I have searched for how to address this but cannot seem to figure it out.
How can I remove the space between the Nav and next section?
Example Image: https://ibb.co/7YcTg4p
*Solved - After adding overflow: auto; inside the #container-bg {} class the white space collapsed and now the nav follows the next section with any space issues.
<header>
<img
src="https://cdn.pixabay.com/photo/2017/09/26/21/45/spiral-
2790215__480.png"/>
<nav class="nav-container">
<ul>
<li>Home
</li>
<li>Portfolio</li>
<li>About</li>
<li>Contact</li>
</ul>
</nav>
</header>
<div id="container-bg">
<div class="content-wrapper">
<h1>Sample text</h1>
<p>More sample text</p>
Contact
</div>
CSS
header img {
width: 40px;
position: relative;
left: 120px;
top: 15px;
}
.nav-container {
float: right;
}
.nav-container ul {
margin: 0;
}
.nav-container ul li {
display: inline-block;
}
.nav-container ul li a {
text-decoration: none;
padding-right: 60px;
position: relative;
font-size: large;
color: black;
top: 22px;
right: 120px;
margin: 0px 0px 0px 20px;
padding: 0px 4px 6px 4px;
}
#container-bg {
background: url(img/img-bg.jpg) no-repeat center center fixed;
background-size: cover;
background-attachment: fixed;
width: 100%;
height: 100%;
}
.content-wrapper {
margin: 0 auto;
width: 80%;
text-align: center;
position: relative;
top: 30%;
}
.content-wrapper a {
background-color: blue;
color: white;
border-radius: 15px;
text-decoration: none;
text-transform: uppercase;
border: 1px solid #ffffff;
padding: 12px 18px;
font-size: 22px;
cursor: pointer;

Answer 1

I think I did not understand the question but it may help
.content-wrapper {
margin: 0 auto;
width: 80%;
text-align: center;
position: relative;
top: 0%; // here is the trick
}

Answer 2

After adding overflow: auto; inside the #container-bg {} class the white space collapsed and now the nav follows the next section without any spacing or gap issues.