* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: Arial, sans-serif;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: linear-gradient(135deg, #667eea, #764ba2);
}

.card {
  width: 90%;
  max-width: 600px;
  background: white;
  padding: 40px;
  border-radius: 20px;
  text-align: center;
  box-shadow: 0 15px 40px rgba(0,0,0,0.2);
}

h1 {
  margin-bottom: 15px;
}

p {
  margin: 15px 0;
  color: #555;
}

input {
  margin: 20px 0;
  padding: 12px;
  width: 100%;
}

button {
  padding: 14px 25px;
  border: none;
  border-radius: 10px;
  background: #667eea;
  color: white;
  font-size: 16px;
  cursor: pointer;
}

button:hover {
  opacity: 0.85;
}

#result {
  margin-top: 25px;
  font-weight: bold;
}