JSFiddle - React, Tailwind, and code Playground

HTML

<div style="" id="scrolling_container">
     <div id="drag_div"></div>
     <div id="frame_div">
         <iframe id="page_iframe" src="http://www.bbc.com/" scrolling="auto" frameborder="0"></iframe>
     </div>
</div>

CSS

#scrolling_container {
    width: 100%;
    height: 400px; 
    position: relative;
    overflow: auto;
}
#drag_div {
    z-index: 10; 
    color: transparent;
    cursor: default;
    position: absolute;
    left: 0;
    top: 0; 
    right: 0;
    bottom: 0;
}

#page_iframe {
    background-color: rgb(255, 255, 255);
    width: 1920px;
    height: 1048px;
}

JavaScript

var draggableContainer = document.getElementById("drag_div");
var scrollingContainer = document.getElementById("scrolling_container");
draggableContainer.removeEventListener('mousedown', draggableContainer.md, 0);
        window.removeEventListener('mouseup', draggableContainer.mu, 0);
        window.removeEventListener('mousemove', draggableContainer.mm, 0);
        var pushed = 0;
        
        draggableContainer.addEventListener('mousedown',
                draggableContainer.md = function(e) {
                    pushed = 1;
                    lastClientX = e.clientX;
                    lastClientY = e.clientY;

                    e.preventDefault();
                    e.stopPropagation();
                    draggableContainer.style.cursor = "move";
                }, 0
        );
                 
        window.addEventListener('mouseup', 
                draggableContainer.mu = function() {
                    pushed = 0;
                    draggableContainer.style.cursor = "default";
                }, 0
        );
                 
        window.addEventListener('mousemove',
                draggableContainer.mm = function(e) {
                    if (pushed) {
                        var offsetLeft = - lastClientX + (lastClientX=e.clientX),
                                offsetTop = - lastClientY + (lastClientY=e.clientY);                         
                            scrollingContainer.scrollLeft -= offsetLeft;
                            scrollingContainer.scrollTop -= offsetTop;
                    }
                }, 0
        );