JSFiddle - React, Tailwind, and code Playground
HTML
<div id="content">
<div id="scr"></div>
</div>
CSS
#content { position:relative; height:500px }
#scr { position:fixed; bottom:auto; background:red; width:50px; height:50px }
JavaScript
var offset = $('#scr').offset();
$('#scr').css('bottom', offset.bottom + 'px');
$('#scr').animate({
bottom: '10%'
}, 1000);