Flip box

I have 3 flipping boxes and I want the background colour (front & back) to be different on each one. I’ve assigned a class to each element. For example step1, step2, step3. When I try update the CSS it has no effect.

This is what I am trying to use for the FRONT
.flip .card .front .step1 {
background: #87dbf9 !important;
}

for the BACK
.flip .icon-color-accent.card .back {
background: #87dbf9 !important;
}

Ticket