custom scroll on specific div

scroll.css

<div id="container">
    <div id="content"></div>
</div>

body { min-height: 1000px }
div#container { height: 200px; width: 300px; overflow: scroll; }
div#content { height: 1000px; }

div::-webkit-scrollbar {
    width: 12px;
}

div::-webkit-scrollbar-track {
    -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.3);
    border-radius: 10px;
}

div::-webkit-scrollbar-thumb {
    border-radius: 10px;
    -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.5);
}