I'm testing some css styles on a blog-like div layout. I used `div{border: 1px solid black;}` to see the divs and look at its positions. 

When this line is in my style, it looks right, but I don't want to have the borders (just had it for development).

As soon as I comment it out everything changes it's positions. Why is this so?

[JSFiddle Link](http://jsfiddle.net/61f2f01q/)

```css
div{border: 1px solid black;} /* Comment this to see the problem */

body{ text-align:center; }

.postTabs{
    float:left;
    background-color: #c8c8c8;
    width: 60px;
    height: 38px;
    padding: 27px 5px 5px 5px;
    border-radius: 50%;
}

.postContent{
    padding: 15px 15px 15px 50px;
    margin-left: 35px;  
    margin-top: 36px;
    text-align: left;
    background-color: #a7a7a7;
}
```

```html
<div class="postContainer">
  <div class="postTabs">asdf</div>
    <div class="postContent">
      <div class="postBody">adf</div>
  </div>
</div>
```