JSFiddle - React, Tailwind, and code Playground

HTML

<div style="position:fixed; left: 10px; top: 10px; background-color: #000000; color: #FF0000;">I Am Fixed</div>
<div id="floater">OccupyJSFiddle!<br>for two lines</div>

JavaScript

var w = $(window).width(), h=$(window).height(),
    minWidth=10,
    minHeight=10, x,y;

var newFloat = $('#floater'), 
    maxHeight = newFloat.height(),
    el, 
    uniqueEls=[],
    i;

for (x=0;x<w;x+=minWidth) {
    for (y=0;y<h && y<maxHeight;y+=minHeight) {
        el = document.elementFromPoint(x,y);
        if (el && $.inArray(el,uniqueEls)<0) {
            uniqueEls.push(el);
        }
    }
}
alert("click OK to move the floater into position.");
for (i=0;i<uniqueEls.length;i++) {
    el = $(uniqueEls[i]);
    if (el.css("position")=="fixed") {
        el.css("top",maxHeight+1);
    }
}

newFloat.css({'position': 'fixed',
             'top': 0,
             'left': 0});