The absolute div gets a new height of 800. How to auto resize the relative container?

```css
.relative {
  position: relative;
  width: 600px;
  height: 400px;
  background: #111;
}
.absolute {
  position: absolute;
  top: 20px;
  left: 20px;
  width: 300px;
  height: 200px;
  background: #fff;
}
```

```html
<div class="relative">  

<div class="absolute"> 
</div>

</div>
```