.embed-responsive-16by9::before{aspect-ratio:16/9}.embed-responsive-2by3::before{aspect-ratio:2/3}.embed-responsive-24by13::before{aspect-ratio:24/13}.embed-responsive-24by4::before{aspect-ratio:24/4}.embed-responsive-3by2::before{aspect-ratio:3/2}.embed-responsive-48by31::before{aspect-ratio:48/31}