I am trying to fix the margins of the files from the right hand side. Any idea where I got wrong here?\

Code:
.content-listing {
overflow: hidden; /* prevents float overflow issues */
}
.content-listing .list-item {
float: left;
width: calc(20% - 16px); /* 5 columns */
margin: 10px;
border-radius: 12px;
overflow: hidden;
background: #111;
box-sizing: border-box;
transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.content-listing .list-item:nth-child(5n) {
margin-right: 0;
}
@media (hover: hover) and (pointer: fine) {
.content-listing .list-item:hover {
transform: translateY(-4px);
box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}
}
