.nb-iframe{margin-bottom:1rem;margin-top:1rem;padding-top:100%;position:relative}.nb-iframe iframe{border:none;height:100%;position:absolute;top:0;left:0;width:100%}@media only screen and (min-width:600px){.nb-iframe{padding-top:56.25%}.nb-iframe--square{padding-top:100%}.nb-iframe--tv{padding-top:75%}.nb-iframe--35mm{padding-top:66.67%}}