As you move closer to the box below the red text will get bigger (up to 5em).
// THE SOURCE CODE var box = $('#demo'), data = $('#data'); box.bind('proximity', {max:300}, function(e, proximity, distance){ // font-size moves between 10px and 40px box.css('font-size', (proximity * 30 + 10) + 'px'); data.text( proximity === 0 ? '[OUT OF BOUNDS]' : 'Distance from box: ' + distance.toFixed(3) + 'px, Proximity: ' + proximity.toFixed(3) ); box.css('background', proximity === 1 ? 'yellow' : ''); });