.embed-responsive-1by3::before{aspect-ratio:1/3}.embed-responsive-16by9::before{aspect-ratio:16/9}.embed-responsive-3by2::before{aspect-ratio:3/2}.embed-responsive-4by3::before{aspect-ratio:4/3}.embed-responsive-48by35::before{aspect-ratio:48/35}.embed-responsive-8by5::before{aspect-ratio:8/5}