My footer burst (browser window resizing)

HTML & CSS
1

Hello,

When I resize the browser’s window : my footer burst.

How I can fix that ?

My page : http://dev.leadcreation.com.au

Previous :

After :

Thank you !

2

Add the line in red:

#supplementary {
  margin: auto;
  [COLOR="#FF0000"]min-width: 920px;[/COLOR]
  overflow: hidden;
  padding: 1.625em 7.6%;
  width: 61%;
}
3

I have added this line but it’s the same :

4

Should I add max-width ??

5

I have tested with #colophon {min-width:920px} but it’s the same :