.text {
  position: relative;
  top: 20px;
  display: flex;
  justify-content: center;
}
.media {
  position: relative;
  top: 30px;
  display: flex;
  justify-content: center;
  box-shadow: 000;
}
.media iframe {
  box-shadow: darkgrey;
  border-radius: 10px;
  position: relative;
  z-index: 1;
}

.img {
  opacity: 0;
  position: absolute;
  top: 0;
  left: 0;
  box-shadow: 0 0 0 9999px #000;
  pointer-events: none;
}
body.dark .img {
  opacity: 1;
}
#btn {
  position: absolute;
  top: 30px;
  left: 30px;
  padding: 8px 16px;
  background-color: black;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}