Currently, I have a scrollbar displaying over part of the page when there is a need for it.

I would like to apply styling to the scrollbar such that it doesn't look so bright and I can have the background area of the scrollbar to be transparent. Hence, I tried to apply styling to it. But the scrollbar still seems to be the same. To test if the styling is working, I gave some styles to the scroll based on this article: https://css-tricks.com/almanac/properties/s/scrollbar/
body::-webkit-scrollbar-track {
box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.3);
}
body::-webkit-scrollbar-thumb {
background-color: red;
outline: 1px solid slategrey;
}
But nothing seems to change.
Don't even see those style attributes in developer tools.

Is it not possible to apply custom styling to the browser scrollbar ? Also, can I give scrollbar styling to a div element ? or It has to be at the root/body level?