Question: Previously, when I had floatings blocks, and i will stop the float, i used ; 

```
<div style="clear:both"></div>

```

But now, i'm solve this problem with pseudo class : 

```
.last_floating_div:after {
 content: ""; 
 display: table;
 clear: both;
}

```

I has always works perfectly. But today... It doesn't work... !
Look at this clear example : <http://jsfiddle.net/YsueS/2/>

I know my problem is a total beginner problem. I have sold this problem so many times... I really don't understand why it doesn't work here !

Many thanks all of you !

Answer: 
Sure - you could clear it via an `:after` clearfix, however the most optimal, lightweight solution would just be to set `overflow:hidden` on the parent, achiving the desired effect with much less coding.

```
#mention {
    overflow: hidden;
}

```

[**jsFiddle here**](http://jsfiddle.net/JSuGN/)

To answer the question directly though, you should have applied the `:after` clearfix to `#mentions` - the parent, instead of the child.. [**jsFiddle here**](http://jsfiddle.net/nqD3m/) it works.
If you just add the `:after` to the id `mention` you will get the desired effect.

```
#mention:after {
  content: "";
  display: table;
  clear: both;
}

```

[JSFIDDLE](http://jsfiddle.net/YsueS/3/)