.embed-responsive-16by15::before{aspect-ratio:16/15}.embed-responsive-16by9::before{aspect-ratio:16/9}.embed-responsive-2by1::before{aspect-ratio:2/1}.embed-responsive-24by13::before{aspect-ratio:24/13}.embed-responsive-24by14::before{aspect-ratio:24/14}.embed-responsive-3by2::before{aspect-ratio:3/2}.embed-responsive-31by48::before{aspect-ratio:31/48}