Why doesn't wrapper spread when specifying float:left?

Question

css

How do I make sure that when specifying any float:left block, the wrapper extends to this block. So far, it turns out like this: jsfiddle.net/w28nocsk
The last blocks were indicated by float: left; and missing box-shadow from wrapper didn't spread to it...

Answer 1

For example, put another c after the floated block (clear: both; a pseudo- element is also possible).
Anyway, here's the article.

Answer 2

Set the wrapperoverflow: hidden;