* File responsive-embeds.js.
* Make embeds responsive so they don't overflow their container.
* Add max-width & max-height to <iframe> elements, depending on their width & height props.
* @since Twenty Twenty-One 1.0
function twentytwentyoneResponsiveEmbeds() {
var proportion, parentWidth;
document.querySelectorAll( 'iframe' ).forEach( function( iframe ) {
// Only continue if the iframe has a width & height defined.
if ( iframe.width && iframe.height ) {
// Calculate the proportion/ratio based on the width & height.
proportion = parseFloat( iframe.width ) / parseFloat( iframe.height );
// Get the parent element's width.
parentWidth = parseFloat( window.getComputedStyle( iframe.parentElement, null ).width.replace( 'px', '' ) );
// Set the max-width & height.
iframe.style.maxWidth = '100%';
iframe.style.maxHeight = Math.round( parentWidth / proportion ).toString() + 'px';
twentytwentyoneResponsiveEmbeds();
window.onresize = twentytwentyoneResponsiveEmbeds;