body
{
 background-color: mediumseagreen; 
}

h1 {
 color: darkred; 
}
#result
{
 background-color: white; 
}

#container
{
 position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: lightgreen;
  border-radius: 5%;
  padding:1.25rem;
}