PHP nth-child in media queries - php

Question

On MyPage are many pictures. In the normal case are 6 pictures in one row. If you change the size of the browser the number of pictures in each row will change. I solved this problem with media queries. In each row the last picture shouldnt get a margin-right: 5px;. But the nth-child wont change its every time the same, thats why the margin isnt correct. What did i wrong?
Here is my php output for the images:
<?php
$sql = "SELECT * FROM bilder";
$result=mysqli_query($db,$sql);
while($row=mysqli_fetch_assoc($result)){
echo "<img class='image' src='$row[bild_pfad]' alt='$row[bild_name]' style='$row[bild_werte]'>";
}
?>
Here is the css:
section{
margin: 0px auto;
width: 925px;
margin-top: 55px;
}
.image{
object-position: center; /* Center the image within the element */
height: 150px;
width: 150px;
object-fit: cover;
margin-right: 5px;
}
.image-margin{
margin-right: 5px;
}
section img:nth-child(6n+6){
margin-right:0;
}
#media only screen and (max-width : 924px) {
/* Five images in each row */
section{
margin: 0px auto;
width: 770px;
margin-top: 55px;
}
section img:nth-child(5n+5){
margin-right:0;
}
}
#media only screen and (max-width : 770px) {
/* Four images in each row */
section{
margin: 0px auto;
width: 615px;
margin-top: 55px;
}
section img:nth-child(4n+4){
margin-right:0;
}
}
#media only screen and (max-width : 615px) {
section{
margin: 0px auto;
width: 460px;
margin-top: 55px;
}
section img:nth-child(3n+3){
margin-right:0;
}
}
#media only screen and (max-width : 460px) {
section{
margin: 0px auto;
width: 305px;
margin-top: 55px;
}
section img:nth-child(2n+2){
margin-right:0;
}
}

Answer 1

I solved my problem. I had to reset the old nth-child code
like this:
section img:nth-child(6n+6){
margin-right:0;
}
#media only screen and (max-width : 924px) {
/* Five images in each row */
section{
margin: 0px auto;
width: 770px;
margin-top: 55px;
}
section img:nth-child(6n+6){
margin-right:5px;
}
section img:nth-child(5n+5){
margin-right:0;
}
}