body {
    
  background: linear-gradient(135deg, #f0f8ff, #e6f2ff);
  font-family: Arial, sans-serif;
}

h1 {
  color: #003366;
}

.container {
  max-width: 500px;         
  margin: auto;
  border: 1px solid gray;  
  border-radius: 6px;
  background-color: #ffffff;
}

#output {
  font-weight: bold;
}