p.caption {
     text-align: center;
     color: white;
     background-color: #333;

 }

 @media screen and (max-width: 991px) {
     iframe {
         margin-left: -25% !important;
         zoom: 1.5;
         -moz-transform: scale(1.25);
         -moz-transform-origin: 0 0;
         width: 100vw;
         height: auto;
     }

     p.caption {
         margin: 0 auto !important;
         padding: 1rem 2rem;
         width: 100%;
         font-size: 16px;
     }
 }

 @media screen and (min-width: 992px) {
     iframe {
         width: 845px;
         height: 475px;
     }

     p.caption {
         padding: 1rem 9rem;
         width: 80%;
         margin: 0 auto !important;
         font-size: 14px;
     }

 }