body {
  font-family: Arial, sans-serif;
  background-color: #f5f5f5;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}
.container {
  background-color: #fff;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
  text-align: center;
  padding: 60px;
}
h1 {
  font-size: 24px;
  color: #333;
}
label {
  display: block;
  font-size: 16px;
  margin: 5px 0;
}
input[type="number"] {
  width: 100%;
  padding: 10px;
  font-size: 16px;
  border: 1px solid #ccc;
  border-radius: 5px;
  margin: 0.5em;
}
button {
  background-color: #007bff;
  color: #fff;
  border: none;
  border-radius: 5px;
  padding: 10px 20px;
  font-size: 16px;
  cursor: pointer;
}
button:hover {
  background-color: #00438b;
}
#result {
  font-size: 18px;
  margin: 20px 0;
  color: #007bff;
}