wp-calypso/packages/global-styles/src/components/global-styles-variation-container/style.scss

@import "@wordpress/base-styles/breakpoints";
@import "@wordpress/base-styles/mixins";

.global-styles-variation-container__iframe {
	border-radius: 3px;
	box-shadow: 0 0 0 1px rgb(0 0 0 / 10%);
	border: 0;
	display: block;
	max-width: 100%;
}