featured image

Hello,

I’m having issues centering featured images on all the posts on my site, I’ve tried adding the following css to my additional css but it doesn’t seem to make a difference, please advise what I am doing wrong. Thank you in advance.

.featured-image {
margin: auto;
}
.page-header-image {
text-align: center;
}

The page I need help with: [log in to see the link]