Demo per Super Marble
<style>#SCcont17597{width: 100%;padding-top: 56.25%;position: relative;}#SCgFrame17597 {position: absolute;top: 0;left: 0;bottom: 0;right: 0;}</style> <div id="SCcont17597"> <iframe id="SCgFrame17597" frameborder="0" allowfullscreen="" mozallowfullscreen="" webkitallowfullscreen="" hspace="0" vspace="0" scrolling="none" src="https://slotcatalog.com/it/slots/Super-Marble?ajax=1&blck=demo-widget" width="100%" height="100%"></iframe> </div>
copia