Border Around Featured Posts

Hi, I have featured posts on my homepage, which I set under the Home Page Settings > Featured Content Options. I want to add a border around each of the featured posts that show on my homepage and am trying to use the following code

#featured-post { 
border: 4px solid #909499;
display: block;
    padding: 10px 2%;
    height: 10%;
}

This however, only places one large border around all off the featured posts. Can you please advise how to alter the code so that each posts gets its own individual box/border? I would post the url, however my site is not yet live. Thank you