JSFiddle - React, Tailwind, and code Playground

HTML

<div id="panel1" name="One"></div>
<div id="panel2" name="Two"></div>

CSS

#panel1 {
    width:50%;
    height:300px;
    float:left;
    background:#2E442E;
}
#panel2 {
    width:50%;
    height:300px;
    float:left;
    background:#5D855C;
}

JavaScript

var isMouseDown = false;
    var mouseJoint;
    var mouse = {
        x: 0,
        y: 0
    };
    var gravity = {
        x: 0,
        y: -1
    };

    var panel1 = document.getElementById('panel1');
    var panel2 = document.getElementById('panel2');

    panel1.onmousedown = onDocumentMouseDown;
    panel1.onmouseup = onDocumentMouseUp;
    panel1.onmousemove = onDocumentMouseMove;
    panel1.addEventListener('touchstart', onDocumentTouchStart, false);
    panel1.addEventListener('touchmove', onDocumentTouchMove, false);
    panel1.addEventListener('touchend', onDocumentTouchEnd, false);

    panel2.onmousedown = onDocumentMouseDown;
    panel2.onmouseup = onDocumentMouseUp;
    panel2.onmousemove = onDocumentMouseMove;
    panel2.addEventListener('touchstart', onDocumentTouchStart, false);
    panel2.addEventListener('touchmove', onDocumentTouchMove, false);
    panel2.addEventListener('touchend', onDocumentTouchEnd, false);



    function onDocumentMouseDown(event) {
        event.preventDefault();
        panel1.style.background = "#2E442E";
        panel2.style.background = "#5D855C";
    }

    function onDocumentMouseUp(event) {
        event.preventDefault();
        this.style.background = "#ff0000";
        console.log(this.id);
    }

    function onDocumentMouseMove(event) {
        
    }

    function onDocumentTouchStart(event) {
        event.preventDefault();
        panel1.style.background = "#2E442E";
        panel2.style.background = "#5D855C";

    }

    function onDocumentTouchMove(event) {
        onDocumentTouchMove.x = event.changedTouches[event.changedTouches.length - 1].clientX;
        onDocumentTouchMove.y = event.changedTouches[event.changedTouches.length - 1].clientY;
    }

    function onDocumentTouchEnd(event) {
        event.preventDefault();
        var elem = document.getElementById((document.elementFromPoint(onDocumentTouchMove.x, onDocumentTouchMove.y)).id);
        elem.style.background = "#ff0000";
    }