// Credit: Nicolas Gallagher and SUIT CSS. .embed-responsive { position: relative; display: block; width: 100%; padding: 0; overflow: hidden; &::before { display: block; content: ""; } .embed-responsive-item, iframe, embed, object, video { position: absolute; top: 0; bottom: 0; left: 0; width: 100%; height: 100%; border: 0; } } .embed-responsive-21by9 { &::before { padding-top: percentage(9 / 21); } } .embed-responsive-16by9 { &::before { padding-top: percentage(9 / 16); } } .embed-responsive-4by3 { &::before { padding-top: percentage(3 / 4); } } .embed-responsive-1by1 { &::before { padding-top: percentage(1 / 1); } }