Angular material layout - issues with flex

I have a problem setting the flex properties of my layout. Here is a plunker: http://ift.tt/1zTOFDh

Here is the link to documentation: http://ift.tt/1y4ro2d

The issue that the flex property of the input (text) and input (button) are not obeying the flex attribute.

What I am trying to achieve is something like that: