Apply
Add a Mask option for this layer (on the layers’ panel bottom) and choose the
Gradient Tool (G) to dark out the lowest part of the background.

Now we shall use the
Rounded Rectangle Tool (U) to represent the primary layer, reserved for the site’s sections, out of which we’ll cut out several circles (pressing the
Alt button and using the
Ellipse Tool (U)).


The layer’s parameters:
Blending Options>Outer Glow
Blending Options>Inner Glow
Blending Options>Gradient Overlay
Gradient’s parameters: