.embed-responsive-2by3::before{aspect-ratio:2/3}.embed-responsive-20by24::before{aspect-ratio:20/24}.embed-responsive-22by24::before{aspect-ratio:22/24}.embed-responsive-24by20::before{aspect-ratio:24/20}.embed-responsive-3by2::before{aspect-ratio:3/2}.embed-responsive-3by4::before{aspect-ratio:3/4}.embed-responsive-4by3::before{aspect-ratio:4/3}