Question: How to make a button be at the bottom of div and at the center of it at the same time?

```css
.Center {
  width: 200px;
  height: 200px;
  background: #0088cc;
  margin: auto;
  padding: 2%;
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
}

.btn-bot {
  position: absolute;
  bottom: 0px;
}
```

```html
<div class=Center align='center'>
  <button class='btn-bot'>Bottom button</button>
</div>
```

Answer: 
For example write like this if you have position absolute:

```
.btn-bot{
   position:absolute; 
   margin-left:-50px;
   left:50%;
   width:100px;
   bottom:0px;
}

```

Note: give margin-left half of the width of the button.

[JSFiddle demo](http://jsfiddle.net/3QguR/12/)
Does the button need to be absolutely positioned? If so, you could specify a width and then a negative left margin:

```
.btn-bot{
    position: absolute;
    left: 50%;
    width: 100px;
    margin-left: -50px;
    bottom:0px;
}

```

[fiddle](http://jsfiddle.net/3QguR/8/)