.responsive-mux { width: 100%; margin-inline: auto; }
.responsive-mux__frame { position: relative; width: 100%; aspect-ratio: var(--desktop-ratio, 16 / 9); background: #111; }
.responsive-mux__frame iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.responsive-mux__status { margin: 8px 0 0; color: #555; text-align: center; font-size: .85rem; }
@media (max-width: 767px) {
  .responsive-mux { max-width: 440px; }
  .responsive-mux__frame { aspect-ratio: var(--mobile-ratio, 1024 / 1820); }
}