body {
  font-family: Arial, Helvetica, sans-serif;
  margin: 0;
  padding: 0;
  height: 100%;
  overflow: hidden;
}
.flip-box {
  background-color: transparent;
  width: 100vw;
  height: 100vh;
  perspective: 1000px;
}
.flip-box-inner {
  margin: 0 auto;
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.8s;
  transform-style: preserve-3d;
}
.flip-box-front, .flip-box-back {
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}
.flip-box-front {
  background-color: white;
  color: black;
}
.flip-box-back {
  background-color: black;
  color: white;
  transform: rotateY(180deg);
}
.overlay {  
  position: absolute;
  bottom: 2%;
  right: 2%;
  background-color: transparent;
  border: none;
  visibility: visible;
}
.overlay-text {
  position: absolute;
  top: 5px;
  left: 10px;
  font-size: 0.6em;
  font-weight: bold;
  background-color: transparent;
  border-radius: 5px;
  padding-top: 4px;
  padding-right: 3px;
  visibility: visible;
}
.overlay-toolbar {
  position: absolute;
  bottom: 3%;
  left: 53%;
  transform: translate(-50%, 50%);
  font-size: 0.6em;
  font-weight: bold;
  background-color: transparent;
  border-radius: 5px;
  visibility: visible;
}
button {
	cursor: pointer;
	text-transform: uppercase;
}
iframe {
  width: 100%;
  height: 100%;
  border: none;
  overflow: hidden;
}