I have a few problems, when I try to style a row that I designed. Here is how the row should look like:

Now I am pretty far, but the content of a row is all below eachother. I already changed to a CSS Grid, but thats why I got this problem!
Here is the snippet of my current code:
.user-part {
width: 100%;
padding-top: 20px;
}
.user-part .list {
width: 100%;
}
.user-part .list .seperation-line {
width: 100%;
background-color: #C4C4C4;
height: 2px;
padding: 0px;
}
.user-part .list .list-header {
display: inline-block;
padding-top: 30px;
padding-bottom: 10px;
}
.user-part .list .list-header .grid-container {
display: grid;
grid-template-columns: 5% auto auto auto auto 10% auto;
grid-gap: 10px;
}
.user-part .list .list-header .grid-container > div {
text-align: left;
padding: 20px 0;
font-size: 18px;
font-weight: bold;
}
.user-part .list .list-user {
display: inline-block;
padding-top: 10px;
padding-bottom: 10px;
}
.user-part .list .list-user span {
font-size: 18px;
width: 100%;
}
/*---Toggle switch---*/
.switch {
position: relative;
display: inline-block;
width: 60px;
height: 34px;
}
.switch input {
opacity: 0;
width: 0;
height: 0;
}
.switch .slider {
position: absolute;
cursor: pointer;
top: 0;
left: 0;
right: 0;
bottom: 0;
background-color: #ccc;
-webkit-transition: .4s;
transition: .4s;
}
.switch .slider:before {
position: absolute;
content: "";
height: 26px;
width: 26px;
left: 4px;
bottom: 4px;
background-color: white;
-webkit-transition: .4s;
transition: .4s;
}
.switch input:checked + .slider {
background-color: #48CE19;
}
.switch input:focus + .slider {
box-shadow: 0 0 1px #48CE19;
}
.switch input:checked + .slider:before {
-webkit-transform: translateX(26px);
-ms-transform: translateX(26px);
transform: translateX(26px);
}
.switch .slider.round {
border-radius: 34px;
}
.switch .slider.round:before {
border-radius: 50%;
}
/*--------------------*/
<div class="user-part">
<div class="list">
<div class="list-header">
<div class="grid-container">
<div>
<span>Id</span>
</div>
<div>
<span>Naam</span>
</div>
<div>
<span>Email</span>
</div>
<div>
<span>Laatste login</span>
</div>
<div>
<span>Gerapporteerd</span>
</div>
<div>
<span>Actief</span>
</div>
<div>
</div>
</div>
</div>
<div class="seperation-line"></div>
<div class="list-user">
<div class="grid-container">
<div>
<span>266</span>
</div>
<div>
<span>Alexander Vreeswijk</span>
</div>
<div>
<span>alexander@vreeswijk.eu</span>
</div>
<div>
<span>2020-10-05 16:22</span>
</div>
<div>
<span>0</span>
</div>
<div>
<label class="switch">
<input type="checkbox" checked>
<span class="slider round"></span>
</label>
</div>
<div>
<a href=""><img src="images/EditUser.png" /></a>
<a href=""><img src="images/DeleteUser.png" /></a>
</div>
</div>
</div>
<div class="seperation-line"></div>
</div>
</div>
The content of a row is all below eachtother, how can I fix that?