.popup {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  height: 0;
  background-color: #fefefe;
  overflow: auto;
  z-index: 15;
  transition: all 750ms ease-in-out;
  padding: 0;
  margin: 0;
}

.popup iframe {
  border: 0;
  width: 100%;
  height: 100%;
}

.popup.visible {
  top: 0;
  height: 100%;
  padding: 5px;
}