space between feature image and post heading on posts page

I am trying to increase the space between the feature image and the post title on the post page. When I test it using developer tools I can create the space but when i try to put that code into Quick CSS it doesn’t work. I tried:

.content .entry-content-wrapper {
padding-top: 10px;
}

and also tried:

.page-thumb
padding: 10px:
}

neither solution worked. please help, thanks!