.embed-responsive-4by3{aspect-ratio:4/3}.embed-responsive-4by3::before{padding-top:75.00%}.embed-responsive-48by25{aspect-ratio:48/25}.embed-responsive-48by25::before{padding-top:52.08%}.embed-responsive-48by31{aspect-ratio:48/31}.embed-responsive-48by31::before{padding-top:64.58%}