/* Wrap iframe in a responsive container */
.responsive-iframe {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 aspect ratio */
  height: 0;
  overflow: hidden;
}

.responsive-iframe iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* Make it smaller only on phones */
@media (max-width: 480px) {
  .responsive-iframe {
    padding-bottom: 75%; /* taller, smaller width */
    max-width: 320px;    /* optional: shrink width */
    margin: 0 auto;      /* center it */
  }
}