This page has its own serif fonts, brown colors and a global style for every
button. The widget below is loaded with one script tag and keeps its own look.
<script src="https://eternalvision.github.io/ecmact/widget/price-widget.js"></script> <price-widget price="49" currency="EUR" label="Pro plan"></price-widget>
The same widget, themed from this page with custom properties:
The page hears the widget through a DOM event. Press "Add to cart".