Stretch and scale a CSS image in the background - with CSS only

Question

I want that my background image stretch and scale depending on the browser viewport size.

I\'ve seen some questions on Stack Overflow that do the job, like

Answer 1

Use the Backstretch plugin. One could even have several images slide. It also works within containers. This way for example one could have only a portion of the background been covered with an background image.

Since even I could get it to work proves it to be an easy to use plugin :).