<html>
<head>
<style>
::-webkit-scrollbar {
    width: 12px;
    height: 12px;
}
::-webkit-scrollbar-track {
    -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.3); 
    -webkit-border-radius: 10px;
    border-radius: 10px;
}
::-webkit-scrollbar-thumb {
    -webkit-border-radius: 10px;
    border-radius: 10px;
    background: rgba(255,0,0,0.8); 
    -webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.5); 
}
::-webkit-scrollbar-thumb:window-inactive {
    background: rgba(255,150,250,0.8);
}
iframe {
    width: 100px;
    height: 100px;
}
</style>
</head>
    <body> 
        <iframe src="scrollable-subiframe-inactive.html"></iframe>
        <div id="fillDIV" style="background-color:lightblue;width:400px;height:400px;overflow:hidden;"> </div>
    </body>
</html>