I have this HTML code:
<div class='container'>
      <div class="post-container">
        <div class="post-thumb"><img src="../images/logo.png" /></div>
      </div>
      //A few other thigs
    </div>  
The post-container is above the other stuff.
 Now I want to centre the post-thumb div in the post-container and the image in the post-thumb.
 But how to do that?
Here is the CSS:
.post-container {
  overflow: auto;
  text-align:center;
}
.post-thumb {
  width:230px;
  height:50px;
  overflow:hidden;
  text-align:center;
  margin-left: auto;
  margin-right: auto;
  margin-top: auto;
  margin-bottom: auto;
}
.post-thumb img {
  width:100%;
  margin-left: auto;
  margin-right: auto;
  margin-top: auto;
  margin-bottom: auto;
}
.container {
  border-top-right-radius: 5px;
  border-bottom-right-radius: 5px;
  box-shadow: 1px 1px 5px #ddd;
  width: 250px;
  height: 100%;
  background-color: #2e3233;
}
 
     
    