html {
  background-image: url("https://sylvatica4.carrd.co/assets/images/image06.png?v=40545ba8");
  background-repeat: repeat;
  
}

.mainbox {
  height: 500px;
  width:500px;
  align-items:center;
  border: 5px brown;
  color:white;
  background-color:pink;
  left: 475px;
  top:100px;
  position:absolute;
}