html, body {
  background-color: #808080;
  margin: 0;
  padding: 0;
  overflow: hidden;
  display: flex;
  height: 100%;
  width: 100%;
  font-family: 'courier new';
  -webkit-animation: bg 20s infinite;
  animation: bg 10s infinite;
  -webkit-animation-direction: alternate;
  animation-direction: alternate
}

.square {
  border-radius: 10px;
  background-color: white;
  height: 100px;
  width: 100px;
}

section {
  position: absolute;
  height: 100%;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

header {
  position: absolute;
  height: 100%;
  width: 100%;
  display: flex;
  justify-content: center;
  top: 20%;
  -webkit-text-stroke: 1px;
  -webkit-text-stroke-color: white;
}

button {
  position: absolute;
  height: 20px;
  width: 60px;
  bottom: 30%;
  font-family: 'courier new';
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(359deg); }
}

@keyframes bg {
  0% {
    background-color: #4467CA
  }
  
  25% {
    background-color: #008000
  }
  
  50% {
    background-color: #FFA500
  }
  
  75% {
    background-color: #FF0000
  }
  
  100% {
    background-color: #A020F0
  }
}

.anim {
  animation: spin 1s linear;
}