OMG you posted a link to a competing themer 👿
lol….just kidding….anyway, this can be done in a few ways, but it’s still going to require you to either do some creative CSS coding, or to modify the theme files (using a child theme), creating a custom shadow graphic image, then using CSS to insert it into the
container or adding it to just below the closing tag of the
tag as a directly inserted image graphic.
Long story short, it can be done but to be honest, this one you need some coding experience or a friend who could do this for you.