Container opacity (transparency)

Hi all!

Does anyone know how i can modify the container and header opacity so the background can be seen through?

I am using this code…

div#container {
background-color: #ffffff;
opacity: 0.8;
}

#header {
background-color: #ffffff;
opacity: 0.8;
}

… But the problem is it also modifies the logo, text ans slides’ opacity.

Any ideas on how i could modify container and header opacity without modifying that of the logo, text and slides inside?

Thanks for your help!