Two stacks, one with animation and the ability to be used as static. The second is completely static.
Both stacks can be used on their own or as a background for something.
In the stack settings, you can specify the height or leave it without a fixed height by enabling Overflow (if necessary).
Sets the color of the circles, two directions of movement (from the center and to the center).
You can choose three types of animation, movement.
Also, it can be used as static by pause.
The size of the circles in the settings is set by changing the scale, from 1 to 3.
Unlike a stack with animation, this one only contains static circles.
You can use both a background for other stacks, and make a background for the page, fixing in different positions.
The size of the circles is created by itself, according to the size of the inner circle, or it is possible to set the size of each circle.
There is a choice of color, either one for all circles, or one for each.
Blur can be used as a small effect.
To use the stack to set the background, the settings provide a choice of the stack (circles) location and fixation so that the circles stay in one place. An example can be seen on the left of the page and on the banner.