Wrapper div height is 0 with floated elements inside

Answer 1

Try this:

<div class="outside" style="border:1px solid #555; overflow:auto">
<div class="inside" style="float:left; width:40px;">CONTENT</div>
<div class="inside2" style="float:left; width:40px;">CONTENT</div>
</div>//Outside container close

Answer 2

Set overflow: hidden on the parent.

<div class="outside" style="border:1px solid #555;overflow:hidden;">
  <div class="inside" style="float:left; width:40px;">CONTENT</div>
  <div class="inside2" style="float:left; width:40px;">CONTENT</div>
</div>

Answer 3

The outer div is collapsing because the two child divs inside of it are floating. The easiest fix for this is to set overflow: hidden; on the outer div.