You may need to have the assistant display in front of or behind other elements on your website. For example, you may want it to cover a static footer, but be covered by an opened cart pane.
This is controlled by the assistant's "stack order", determined by the CSS property "z-index". You'll need to assign the assistant a z-index value that is higher than any element the assistant should cover and lower than any element the assistant should be covered by.
For example, if the site has a footer with z-index of 50 and a cart pane with z-index of 200, you may want to give the assistant a z-index of 100 so that it will cover the footer but not the cart pane. You can do that with a CSS rule like the following:
mavenoid-assistant { z-index: 100 !important; }
You may need to experiment to find the right number to use.