On my website, I'm unable to change the background of the front-page card using CSS. I cannot change the background color of the card-header either. I'm using neocities to host my website.

CSS CODE
(how to view HTML code right click and press “View Page Source”)

I'm currently using

.card {
  background-color: #2e2747;
}

and it doesn't show up when I click Inspect → Style Editor → style.css