html {
  padding: 0;
  margin: 0;
}

body {
  background-color: inherit;
}

.container {
  display: flex;
  justify-content: center;
  align-items: center;
}

button {
  width: 30vw;
  height: 30vw;

  border: none;
  border-radius: 50%;
  background-color: YellowGreen;

  display: flex;
  justify-content: center;
  align-items: center;

  transition: 1s all ease;
  cursor: pointer;
  outline: none;
}
button:hover {
  background-color: SeaGreen;
}
button span {
  margin-left: 10px;
}



:-webkit-full-screen {
  background-color: yellow;
  border: 5px solid Thistle;
}
:-moz-full-screen {
  background-color: yellow;
  border: 5px solid Thistle;
}
:-ms-fullscreen {
  background-color: yellow;
  border: 5px solid Thistle;
}
:fullscreen {
  background-color: yellow;
  border: 5px solid Thistle;
}