* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.iframe {
  width: 100vw;
  height: 100vh;
  border: 0;
}

.button {
  border: 0;
  padding: 0;
  width: 70px;
  height: 70px;
  overflow: visible;
  text-align: inherit;
  background: #3A3535;
  border-radius: 500px;
  color: white;
  text-align: center;
  cursor: pointer;
  position: fixed;
  top: 50vh;
  transform: translateY(-50%);
  left: 20px;
  transition: transform ease 0.3s;
}

.button--next {
  left: auto;
  right: 20px;
}

.button:hover {
  transform: translateY(-50%) scale(1.05);
}