body
 {
  background: #f3f3f3;
 }
 
 h1{
   text-shadow: 0.03em 0.03em 0.01em #000;
   letter-spacing: 0.03em;
   text-align: center;
 }
 
 
 
button {
  
  flex: 1;
  margin: 0.25em;
  text-align: center;
  font-size: 1.2em;
  width: 3em;
  height:3em;
  background-color: orange;
}
 
.caja {

   font-family: Times, serif;
   color: white;
   box-shadow: 0 0 5px 5px #888;
   padding:1.5em;
   background-color: #2E8B57;
   text-align: center;
}


.pantalla
{
color: black;
font-size: 1.4em;
}