An (incomplete) polyfill of ::region()
functional pseudo element.
Work in progress.
<script src="path/to/regionrulepolyfill.js"></script>
<script>
Region('#region1').addRegionRule('p', {
color: 'red',
backgroundColor: 'green'
});
Region('#region2').addRegionRule('h1', 'margin-right: 100px;');
</script>
In environments without basic CSS Regions supports, this polyfill works on Adobe's CSS Regions Polyfill.
MIT