CSS - ::after pseudo element positioning and dimension issue - css

Question

I have 2 images with transparent background and need to put one on top of each other with the same positioning:
1 spinning (underneath)
1 fixed (above)
I need to have the whole image composition to be centered and to have its size adjusted depending on the window size.
I used an ::after pseudo element for the fixed one but couldn’t get its position and size to follow the spinning one.
I suppose the background-size property should be involved but didn’t manage to use it properly.
Would appreciate any advice, even if it involves going with a totally different approach than the ::after pseudo class.
Many thanks.
body{
width: 100%;
height: 100%;
background-color: #000;
text-align: center;
color: #fff;
}
.main-container{
background-color: #00f;
width: 50%;
margin: 0 auto;
}
.engine-container{
}
.engine-complete{
position: relative;
width: 100%;
height: auto;
margin: 0 auto;
}
.engine-complete::after{
content: "";
position: absolute;
width: 191px;
height: 192px;
top: 1px;
left: 0;
background-image: url(https://image.ibb.co/jOqNma/engine1_crpd.png);
}
.engine-rotating{
width: 50%;
height: auto;
}
.spin {
animation-duration: 15s;
animation-name: spin;
animation-iteration-count: infinite;
animation-timing-function:linear;
animation-play-state: running;
}
#keyframes spin {
from {
transform:rotate(360deg);
}
to {
transform:rotate(0deg);
}
}
<div class="main-container">
<h1>spinning engine</h1>
<div class="engine-container">
<div class="engine-complete">
<img src="https://image.ibb.co/nwOKXF/engine1.png" width=191 height=192 class="engine-rotating spin"/>
</div>
</div>
</div>

Answer 1

Something like this?
EDIT: Instead of setting the image as a background using the ::after pseudo-class, I added the fixed image into the html. I also eliminated one of your containers.
I centred the animated image using text-align:center and centred the fixed image using position: absolute
I set both images to 30% width relative their parent .engine-container
The fixed image has a higher z-index than the animated image so that it always appears over it. The images also change size accordingly, relative to window size.
body {
width: 100%;
height: 100%;
background-color: #000;
text-align: center;
color: #fff;
}
.main-container {
background-color: #00f;
width: 50%;
margin: 0 auto;
}
.engine-container {
text-align: center;
position: relative;
}
.engine-rotating,
.engine-fixed {
width: 30%;
}
.engine-fixed {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%) rotate(0deg);
z-index: 5000;
}
.spin {
animation-duration: 15s;
animation-name: spin;
animation-iteration-count: infinite;
animation-timing-function: linear;
animation-play-state: running;
}
#keyframes spin {
from {
transform: rotate(360deg);
}
to {
transform: rotate(0deg);
}
}
<div class="main-container">
<h1>spinning engine</h1>
<div class="engine-container">
<img src="https://image.ibb.co/nwOKXF/engine1.png" class="engine-rotating spin" />
<img src="https://image.ibb.co/jOqNma/engine1_crpd.png" class="engine-fixed" alt="">
</div>
</div>
UPDATE
Heres what I came up with:
A similar effect using ::after. I was able to achieve this by inserting the image url into the content: rule, rather than setting a background image.
body {
width: 100%;
height: 100%;
background-color: #000;
text-align: center;
color: #fff;
}
.main-container {
background-color: #00f;
width: 50%;
margin: 0 auto;
}
.engine-container{
text-align: center;
position: relative;
}
.engine-rotating{
}
.engine-container::after{
content: url('https://image.ibb.co/jOqNma/engine1_crpd.png');
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%) rotate(0deg);
z-index: 5000;
}
.spin{
animation-duration: 15s;
animation-name: spin;
animation-iteration-count: infinite;
animation-timing-function: linear;
animation-play-state: running;
}
#keyframes spin{
from {
transform: rotate(360deg);
}
to {
transform: rotate(0deg);
}
}
<div class="main-container">
<h1>spinning engine</h1>
<div class="engine-container">
<img src="https://image.ibb.co/nwOKXF/engine1.png" class="engine-rotating spin" />
</div>
</div>

Answer 2

Set position for .engine-complete::after to relative
.engine-complete::after {position: relative}
body{
width: 100%;
height: 100%;
background-color: #000;
text-align: center;
color: #fff;
}
.main-container{
background-color: #00f;
width: 50%;
margin: 0 auto;
}
.engine-container{
}
.engine-complete{
position: relative;
width: 100%;
height: auto;
margin: 0 auto;
}
.engine-complete::after{
content: "";
position: relative; /* this was changed */
width: 191px;
height: 192px;
top: 1px;
left: 0;
background-image: url(https://image.ibb.co/jOqNma/engine1_crpd.png);
}
.engine-rotating{
width: 50%;
height: auto;
}
.spin {
animation-duration: 15s;
animation-name: spin;
animation-iteration-count: infinite;
animation-timing-function:linear;
animation-play-state: running;
}
#keyframes spin {
from {
transform:rotate(360deg);
}
to {
transform:rotate(0deg);
}
}
<div class="main-container">
<h1>spinning engine</h1>
<div class="engine-container">
<div class="engine-complete">
<img src="https://image.ibb.co/nwOKXF/engine1.png" width=191 height=192 class="engine-rotating spin"/>
</div>
</div>
</div>