modules/jumpstart_ui/lib/js/jumpstart_ui.js
(($, Drupal ) => {
Drupal.behaviors.jumpstartUi = {
attach: function attach(context, settings) {
$('figure .media-entity-wrapper.video', context).each((i, video) => {
$(video).closest('figure').css('width', '100%');
});
},
};
})(jQuery, Drupal);