I'm trying to make a `div` with both `width` and `height` set to `auto` become centered on the screen, both vertically and horizontally. Here's the current CSS I've done, please any help.

```
 #popup {
    position: absolute;
    margin: auto;
    height: auto;
    width: auto;
    display: table;
    padding: 10px;
    max-width: 650px;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}

```