I see what you describe a the semi-transparent, but I do not see the gradient with this code. It was also not clear you were using the custom:-mod-card from your original post.
For future questions, check out this (#11) for posting and formatting your code.
The link to the dedicated card-mod thread
When you apply the mod to the area card do you get the results you want?
type: area
area: bedroom
card_mod:
style: |
.container::before {
background: none !important;
}
.container {
background: none !important;
}